Q: I love Halloween stories. But why are some houses haunted, while others are not?

A: No one knows for sure. But of the thousands of hauntings reported every year, most involve properties that either were the site of great physical or emotional suffering, or the location of a sudden or particularly tragic death.

Examples in the first group include Southern plantations frequented by the ghosts of mistreated slaves or their owners, and the dozens of old asylums and prisons where former occupants endured years of unspeakable cruelty or isolation.

When those people died, experts in the paranormal say, they left behind powerful sources of energy that continue to manifest in various ways – from barely audible sounds heard only by a few to full-blown apparitions verified by hundreds of witnesses.

The second group of hauntings include places like New York’s Clinton Street Brownstone, said to be visited often by the ghost of a young girl who died while undergoing an illegal abortion performed by her father, or the dozens of highways where the spirits of those killed in violent car accidents are said to return to the scene of their worldly demise.

Some believe that spirits involved in that second category simply don’t understand that their time on Earth has passed; because death came so suddenly, they linger about in a sort of cosmic confusion. Several such hauntings reportedly have been ended after a medium conducted a seance to contact the unwelcome spirit, explained how its body died and then told it that it was time to move on to its next destination.

Of course, most homes are filled with happy memories, and their former occupants died peacefully – which may explain why most of us live in places that aren’t haunted.

Q.: Have you ever heard of a haunted mansion called “Hickory Hill” in Illinois? My father used to tell me ghost stories about it when I was a little girl, but he died many years ago, and I don’t know if his stories were true.

A.: Hickory Hill, sometimes called “The Old Slave House,” stands upon a bluff on the outskirts of the tiny town of Equality in southern Illinois. It was built by John Hart Crenshaw, who moved his family into the mansion’s two lower-level floors in 1838.

The Crenshaws were rather wealthy and were devout churchgoers, but they kept a terrible secret: John Crenshaw had created a virtual prison in his attic, where he would warehouse free blacks he had kidnapped. He would then force them to work in the dangerous salt mines nearby, or sell them to slave-traders a few miles to the south.

Even by slave standards, Crenshaw’s captives were treated miserably. Dozens were sometimes locked in the attic’s 12 makeshift cells, many of them shackled to the floor and walls. Miscreants would be flogged on the bloodstained whipping posts in the narrow hallway, or suffer even greater torture at the hands of Crenshaw and his cronies.

It’s not clear whether Hickory Hill’s hauntings began before or after Crenshaw’s slave operation was shut down and the old man died in 1871, for he was not the type to share such dark details. But by the early 1900s, dozens of people who visited the home told of hearing disembodied shrieks and mournful sobbing floating down from the vacated attic, and the mysterious rattling of chains that had long since been removed.

The home’s notoriety spread, and exorcist Hickman Whittington finally was called to rid the property of its demons around 1923. It was Hickman’s last assignment: Foolishly trying to work alone, he fled the attic in horror shortly after he arrived, and he died just a few hours later.

The exorcist’s death only added to the mansion’s infamy, so its new owners converted Crenshaw’s old downstairs living quarters into a small museum and started charging visitors a dime to come in.

Profiting from the home’s sorrowful past may have angered the spirits even more, for the hauntings seemingly grew worse. During the next several decades, more than 100 people – some motivated by the promise of cash rewards, others by sheer curiosity – would try to spend an entire night in the aging attic. All of them failed, including two decorated Marines who, in 1966, fled in terror after their kerosene lantern was inexplicably blown out and they were soon surrounded by swirling, ghastly figures and “a cacophony of voices.”

In 1978, a local TV reporter armed with more modern equipment finally became the first visitor to spend the evening in the attic in more than a century. He recounted hearing eerie sounds throughout the ordeal, and partially credited his success to the crew he had enlisted to stand outside the home and yell their support. Some experts say the constant racket made by the group may have confused or even scared the spirits into remaining relatively quiet.

The Old Slave House was purchased several years ago by the state of Illinois, which then posted “No Trespassing” signs around the property and closed it to the public. Some hope the mansion one day will be restored and reopened, but others say it should stay forever closed to respect the spirits who may still reside there.

– David W. Myers is a 20-year veteran of the newspaper and magazine business, having previously covered real estate for the Los Angeles Times and Investor’s Business Daily.