The whole "ghosts should only be horror" doesn't sit well with me. I like the idea of the various spirits from history hanging out and dishing the dirt on people. Or whining that the current owners of their ancestral homes have horrid tastes. The kind of small, humanizing moments so blatantly missing from a lot of stories about ghosts.
Have you read Waiting For the Galactic Bus and The Snake Oil Wars by Parke Godwin? Yeah, they're a science fictional take on the whole question, and it's more about the afterlife rather than ghosts haunting a place. But it's still in the same ballpark, a giggle at times, and though provoking at other times.