From hitchhikers to helpful weather watchers to Hollywood stars – ghosts can come in many different forms.
There are plenty of ghost stories from all over the country but we narrowed it down to these: the most famous ghosts in American history.
Probably the most famous ghost in American history is the Bell Witch, a poltergeist who messed with the Bell family of Adams, Tennessee, from 1817 to 1821.
According to BellWitch.org, a spirit claiming to be "Old Kate Batts's witch" drove John Bell, Sr. and his kids to the brink of insanity with constant knocking and scratching sounds, and physical assaults like hair-pulling.
"And by the winter of 1817, the children were even being slapped by invisible hands." This phenomena began when John saw a weird animal that looked like a black dog with a rabbit's head out in his field, which is fairly weird, even by poltergeist standards.
While Kate liked to harass the Bells' youngest daughter Betsy and father John, she showed a lot of affection for Bell's wife, Lucy, giving her fruit and singing her hymns.
If you're the kind of person who wants to climb underground and possibly be harassed by a ghost, great news: the Bell Witch Cave, where Kate's ghost is said to reside since leaving the Bells behind in 1821, is a popular tourist spot.
We'll hear from Chicago again later in the list, but perhaps its best known ghost legend is about Resurrection Mary, who's also likely the most famous example of the "vanishing hitchhiker" type of ghost.
Here's how things basically go: a dude drives down Archer Avenue and sees a girl in a party dress walking down the road.
The dude asks the girl to get in his car and she agrees, but sits very quietly in the car until she asks to be let out at Resurrection Cemetery… and then the twist – she completely disappears because, surprise, she was a ghost all along.
The generally accepted version of the story is that Mary was a girl walking home from the Oh Henry Ballroom after her boyfriend was a jerk to her and then while on Archer Avenue, she was hit by a completely different jerk who subsequently drove away and left the poor girl to die and be a ghost forever.
There have been a number of attempts to identify Mary with one of the thousands of residents of Resurrection Cemetery, but so far, no such luck.
At least one ghost has been known to actually save lives and has done so since 1822.
That guy is the Faceless Gray Man of Pawleys Island, a coastal city of South Carolina.
The Gray Man is typically described as having no face, and dressing like a gray pirate.
Basically his deal is that he shows up when a hurricane or other severe storm is about to hit, and if you see him, you'll be protected from the storm.
The story is that he was a guy traveling from Charleston to see a young lady when he and his horse got sucked down in the mud of South Carolina's gross marshes.
Since then, he's roamed the coastline, looking for his love and doing some meteorology on the side.
The Gray Man came to national attention in 1989 after appearing on Unsolved Mysteries when a couple claimed that the Gray Man saved their house from Hurricane Hugo after they waved at him on the beach.
While the name "Cottage City Poltergeist" might not ring any bells, you might be familiar with the book it inspired and its movie adaptation: William Peter Blatty's The Exorcist.
Blatty's novel tells the story of a young girl possessed by a demon who makes her spit up pea soup and hurl profanity at her mom and some priests.
"Is there someone inside you?" "Sometimes." According to Washington City Paper, the real-life case from 1949 actually centered around a 13-year-old boy from Cottage City, Maryland, who was known by the pseudonym "Roland Doe." If you've seen the movie, you probably have an idea of the phenomena Roland's family experienced: Roland plays with a Ouija board and soon there's shaking beds, weird noises, sheets pulled off the mattress, writing appearing on the boy's skin, and so on.
The boy was ultimately moved to a hospital in Saint Louis, where a number of Jesuit priests performed an exorcism, during which more strange stuff happened.
The boy seemed cured afterward, so the priests felt confident in their diagnosis of demonic possession and the Doe family converted to Catholicism, so score one for the church.
In this case, we've got an apparition who's actually more famous for his accomplishments in life than for being a ghost: Abraham Lincoln.
Lincoln's friend and biographer Ward Hill Lamon says Lincoln was warned by a number of dreams about his assassination in 1865, and since then, his ghost has popped up in a number of different locations, including his own grave and Ford's Theatre.
But he's most commonly spotted in the White House, including, naturally, the Lincoln Bedroom.
There have been claims that numerous heads of state have been shocked by the ghost of Abraham Lincoln in the last 150 years, including Queen Wilhelmina of the Netherlands who fainted after opening the door to find Honest Abe standing there.
Eleanor Roosevelt's dog also used to bark at the ghostly Emancipator.
But maybe the best story is that of Winston Churchill, who once stepped out of the bathtub and walked into the bedroom to reportedly see Abe standing by the fireplace.
Completely naked and ashing his cigar, Churchill quipped, "Good evening, Mister President.
You seem to have me at a disadvantage." Thanks to the 1977 book The Amityville Horror by Jay Anson and the subsequent film adaptation, you're probably familiar with the experiences of the Lutz family in their house in suburban Long Island, New York.
If not, here's the short version: The Lutzes moved into their home in Amityville after the house had remained empty for over a year following the murder of six members of the DeFeo family by Ronald DeFeo, Jr.
Soon, weird stuff was happening, like voices yelling at priests, flies swarming in the house even in winter, cold spots and unpleasant smells, vivid nightmares, a rotating crucifix, physical attacks on the family, and appearances by a freaky pig monster named Jodie.
"What else does Jodie tell you? "She says she wants me to live here forever and ever, so we can all play together." Those were just a few of the experiences that led to the Lutzes abandoning the house and leaving their possessions behind.
If that stuff keeps you up at night, don't worry – it's pretty much all fake.
Further evidence of skullduggery is the involvement of Ed and Lorraine Warren, the charlatans whose con artistry is the inspiration behind such popular but still totally fake films as The Conjuring and Annabelle.
The Warrens investigated the house in 1976 and took a series of infrared photographs, including the super-famous and super fabricated photo of a demonic boy in a doorway.
But all of this hasn't stopped the Amityville haunting from making an impression on the American psyche.
Zona Heaster lived in Greenbrier County, West Virginia, in the late 1800s.
In 1896, she married a drifter named Edward Shue, who killed her.
But Zona's death was attributed to natural causes,after Shue freaked out the doctor until he ran away.
Fortunately, Zona's mother Mary Jane didn't trust Shue for a second – mostly because, for four nights, her daughter's ghost allegedly appeared to her and explained that Shue had broken her neck.
To prove it, Zona turned her head completely around until her ghost face was backwards.
Naturally, Mary Jane demanded an autopsy, and, surprise, it turned out Zona's neck was broken.
During Shue's subsequent trial, the prosecutor tried to keep Mary Jane's ghostly visitor secret, but the defense asked about the ghost extensively in an attempt to undermine Mary Jane's credibility.
This strategy backfired, because if anyone in history has ever believed in ghosts, it is definitely West Virginia hill people from the 1800s.
Shue went to jail, Zona's ghost was never seen again, and the state erected a historical marker about the Greenbrier Ghost as a sort of "sorry you got murdered" gift.
In 1848, Kate and Margaret Fox, ages 12 and 15 respectively, managed to leverage their ability to make their toes pop on command into international celebrity, first by fooling their parents with the noises.
"Their two young adolescent daughters Kate and Margaret approach them and say 'well it so happens that these bangs are spirit raps.'" After first attributing the supernatural "rapping" to the devil, they changed their story, altering their correspondent to Charles B. Rosna, a traveling peddler who had been murdered and buried in their basement.
Developing a system of communication with the late Mr. Rosna via knocking, the Fox sisters became the most famous supernatural rapping act in American history.
Their celebrity led to the emergence of Spiritualism in America, a belief system in which people look to spirits for guidance.
Although in later years the sisters would confess that their seances were a hoax and renounce Spiritualism in no uncertain terms, that hasn't stopped people from asking their dead uncles for advice.
Here's Chicago popping up again with Bachelor's Grove, an abandoned cemetery that's said to be haunted.
While the most common sightings are of featureless orbs of light or blobs of ectoplasm, many visitors report seeing a spectral farmer and his horse, a vanishing black dog at the cemetery's entrance, eerie figures in monks' robes, and a ghost with two heads.
In fact, the cemetery is so overflowing with haunts that many visitors report phantom vehicles almost running them off the road near the cemetery.
But perhaps the most famous ghost of all in Bachelor's Grove is the so-called "Madonna," or "white lady," an immaterial girl dressed in white.
On nights of the full moon, she can be found wandering the graveyard carrying a baby, or apparently sometimes in the full daylight sitting on a tombstone, as in a famous photo by the Ghost Research Society from 1991.
In the days before Prohibition, the William J. Lemp Brewing Co. was the beer king of Saint Louis thanks to their Falstaff brand of beer.
But today, the Lemp family is better known for killing themselves and filling their house up with ghosts.
Four members of the Lemp family shot themselves between the years of 1904 and 1949, and now their ghosts are thought to haunt the halls of their family home.
If those four suicides weren't enough, there's also the ghosts of family members who died of natural causes, and even the ghost of a person who probably didn't actually exist named Zeke.
He's supposedly William Sr.'s illegitimate son who died in captivity, hidden away in the attic.
The mansion is an inn and restaurant these days and it hosts numerous ghost tours, capitalizing on its reputation as one of the most haunted houses in America.
From the vantage point of the 86th floor observation deck of the Empire State Building, guests can enjoy breathtaking, picture-perfect views of the Big Apple.
And until 1947, it was also, sadly, a spot from which deeply depressed people could jump to their deaths.
A suicide-prevention fence was installed in the late 1940s after a spate of deaths, including that of 23-year-old Evelyn McHale.
McHale's death came to be known as "The Most Beautiful Suicide" after her photo ran in Life magazine.
McHale reportedly never completely left this earthly realm — her ghost is said to still haunt the Empire State Building more than 70 years later.
Marilyn Monroe is arguably the most famous actress that Hollywood ever produced.
Perhaps because of her sad and somewhat mysterious overdose-related death in 1962 at the age of 36 in her Los Angeles area home, her ghost reportedly restlessly wanders around various Hollywood haunts the actress frequented during her fleshly years.
"Her gentle haunted image continues to appear." According to Los Angeles TV station KCET, Monroe and Joe DiMaggio honeymooned at the Knickerbocker Hotel, and previously met at the building's bar for quiet dates.
In the women's powder room just off from the watering hole, Monroe was frequently spotted staring at her ghostly image in the mirror.
Per The Hollywood Reporter, ghost spotters have seen the former Monroe similarly looking in a mirror in various other spots.
Even spookier: A thick, pink mist that fans believe to be Monroe's presence, often hangs in the air outside of her final resting place in Westwood Village Memorial Park.
If you or anyone you know is having suicidal thoughts, please call or chat online with the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).
See more at The Most Famous Ghosts In American History