A childhood belief about ghosts

I used to believe that if you looked into a mirror with the lights out, say "Bloody Mary" three times, and throw water at the mirror. In your sleep, she would come to you and wake you up. She would ask you, "Do you know where my husband is?" because as the story goes, her husband cheated on her and ran away with his mistress. If you say no, then she would scratch you for wasting her time. If you said yes, then she would kill you.

One night, I wanted to try it out... nearly scared myself half to death. I went to sleep that night and had a dream that she came to me. I woke up the next morning and noticed a long scratch down my leg. I probably just scratched myself somehow in my sleep, but since then I have been afraid to sleep in a room with a mirror in it by myself.