In honor of Halloween go have some fun reading this Fark thread full of "scariest true stories". Just scroll until you see a lot of text, roll back, and read. Nothing of the sort has ever happened to me, probably because I don't believe in ghosts.
I do, however, believe in my own ability to scare the bejeezus out of myself, and in the ability of sneaky m-f'ers who are out to scare the bejeezus out of me. So just back off and leave the light on, eh?