^You haven't seen Warm Bodies have you?
I actually have a synopsis written somewhere on an idea I had for a ghost movie that treated ghosts with a degree or two of eeriness while also a bit of a "romance" plot between one of the character and a female spirit (even had a love scene in it.)
Anyway, it seems with ghost movies it's usually the more stricter scary/horror avenue. But not quite the same as, say, vampires, zombies or werewolves when it comes to using them as the scary antagonists in a movie. Normally they go to straight-up horror rather than the popcorn movie monster villain like we have with zombies.