I'll be honest here--while I do have a John Bell in my ancestry (and seriously, who doesn't?), I haven't tried to confirm any family ties to this story. As fun as it is to be frightened by a story, I'm not sure I want to have a biological link to it.
Anyway, the short version goes something like this:
Farmer John Bell bought land and a home in what is now Adams, Tennessee in the early 1800's. One day while out in the field he encountered a strange animal with the head of a rabbit and the body of a dog. When he went to investigate, it promptly disappeared.
Shortly after this, the family began to hear strange noises in the walls along with mysterious moving objects and children complaining of an unseen aggressor pinching and slapping them. John Bell's youngest daughter, Betsy, seemed to receive the brunt of these attacks. Not surprisingly, Betsy was a young lady of marriageable age--prime poltergeist bait. Occurrences worsened when Betsy became engaged to Joshua Gardner, eventually leading to an end to the engagement.
The entity continued to harass the family for years until John Bell's death in 1820, but it's said that it promised to visit Bell's direct descendant in 107 years.
Of course my mother, having a wide-eyed audience hanging on her every word, often embellished the story, and without a doubt failed to mention that 107 years had come and gone. What she would do, which I'm hesitant to do to my own children, was end the story as every good ghost story should end--with a loud BANG!!
Ah, good times.
For a much better account of the Story of the Bell Witch, here are a few links: