Like the previous episode, I always wonder why people who see the people who they have killed as "ghosts" take them at their word that they will help them achieve their goals.  I've always thought the "evil twin" was a funny idea - that in birth one twin was all goodness and the other was evil.  What happens when you have triplets or more?  Is it evenly divided amongst them?  What happens if the good one happens to be a redhead and the parent remarries?

All that being said it wasn't a bad episode and the twist at the end was good, even if you could see it coming from the setup.  I'm just curious why their ghosts would be "required" to haunt their home.