It's tricky to say what counts as the spirit of a former human - identifying alleged ghosts is often speculative to say the least. Scotland has tales of grey pipers and grey ladies that herald the death of a member of a family, as have Ireland with their banshees, but whether these are ghosts of the dead is unclear. I remember a tale, allegedly true, by Elliott O'Donnell, about a bogel, a North of England/Scottish spirit that heralds death and, in the tale, actually pursued a man who later died. Of course, whether these apparitions cause death or predict it is open to debate. In Africa, and possibly India, I recall there are stories of people wasting away through believing they are haunted (due to a curse they have incurred).
In terms of a physical assault by a ghost or something of that nature, I don't recall any genuine stories, though I've read that many that there must surely be one. Then again, as fluffle says, if seeing a ghost is rare, then witnessing one murdering another person must be...well, LOTS rarer.