All I can do is speculate.
You tell me. Are all those people who think they're Napoleon actually Napoleon?
If you are going to claim they were ghosts, will you please define ghost for me? Because my understand of the word is that it is the "spirit" of a dead person. Is that what you mean by ghosts?
hey, I'm no Napoleon, but Chavez does reserve an empty chair at the dinner table served with food for Simon Bolivar!
if we start defining what is or is not a ghost is will just open a big can of worms...
lets say I tell you a ghost is a disembodied soul, then you'll ask me to define soul, or to empirically prove that it exists, etc... not in the mood to play those games man.
to quote from an excellent spanish horror movie: a ghost is an event disposed to repeat itself. un fantasma es un evento dispuesto a repetirse (el espinazo del diablo)
peace!