I think my present favorite story for sheer creepiness is the murderous ghost of Carl Pruitt
http://www.prairieghosts.com/pruitt.html
MrRing left a post in the Killer Ghosts subforum about it.
Now most people who see ghosts get completely creeped out about them, and fair enough. They shouldn't be there, and you get the whole skin crawl and adrenaline shiver which is your body saying "Wrongness! Run!" The difference with the Pruitt grave issue is that his ghost seems to have been unusually active in killing people who disturbed his headstone with his signature weapon, a length of chain. This is full-on horror movie material imo, except it is supposedly all true. Has anyone heard differently? I have looked for a debunking, but there doesn't seem to have been one.