This guy walks into a hotel and wants a room, but the clerk tells him the only room available is on the thirteenth floor and it is haunted. The guy says he doesn't care. He gets all ready for bed when he sees a peanut butter slice and he thinks Damn I love peanut butter. He's just about to eat it when he hears "Don't eat the peanut butter slice!" and he jumps out the window and dies. Another guy gets the same room, hears the same thing, and dies the same way. A third guy walks into the hotel and asks for a room and is told by the clerk that the only room available is on the thirteenth floor and is haunted and two people have died there already. The guy says he doesn't care and goes up and gets ready for bed when he sees the peanut butter slice. He's just about to eat it when he hears, "Don't eat the peanut butter slice!". "Shut up, I saw it first" the guy yells and eats it. Then he hears the voice again. "I told you once I told you twice I wiped my butt with the peanut butter slice!"

I heard this when I was 9 I think but this was the first one to come to mind just now.