This may be an old episode of the Hitchcock hour, but it's in reruns. In this episode James MacArthur, marries a girl for her money. She falls out of grace with her mother, because she won't give up her husband. The mother sees him for what he is a fortune hunter. So he tells the wife to pretend she's committed suicide to get the mother back. Then tells her to write a letter to her mother,saying she's going to kill herself. He dictates the letter, and she writes it... But when he lifts up the letter to put into the envelope it's blank. there is no writing on it. James should not have let that side of the paper, be visible to the camera.