Cousin Nancy was telling us ghost stories once, and my father heard and said, "Don't believe a word of this. There's always something material behind it. Now I'll tell you a ghost story."
And he told us how his mother died when he was young, and he quit school after third grade and stayed home to take care of the house. One day after his father went to work he combed his sister Anna's hair and sent her off to school with the others. And then he was alone in this old farmhouse, in the kitchen washing dishes. There was a knock, knock, knock. He opens the door, and there's nobody there. Then this happened again. Knock, knock, knock, and no one was there. Then the third time he heard it he said, "Oh, that must be the ghost of my mother."
So he went outside and walked around the house. He sort of relished the feeling of his mother being there with him. Then he heard knock, knock, knock. He looked up at the side of the house, and the old washtub was banging in the wind.