What he means is that the spirit exists, and leaves. The body is just dead. There are no human spirits that linger for long. I myself have had a close friend die. The TV, Game system, and lights would all switch back on after I turned them off. This lasted for a couple days and it stopped. I can only conclude that my friend wanted to tell me he was okay, and that he was still on and he hasn't changed. What PK means is that human souls don't return, but demons and other twisted beings and humans do. That is what you speak to. This is who you let into your home. Not your grand dad, or whoever you want to talk to.