I think somebody who would be completely unhappy about being a ghost, somebody that we think of as being quite vain would be good.
Somebody like Casanova or Marie Antoinette, or somebody who would just be so frustrated that they couldn't get their hands on somebody else. Shakespeare would be good, because he'd have so many plays and he still needed to write, and he was so sorry he'd stopped and retired so early. I really think he would be good. It would be fertile ground there, that kind of character.