This has to be the biggest long shot of the lot!
2, 3, maybe 3.5 years ago, a thread came up where a mnetter did a link to a short story. I loved it. All I can remember though, is that it was set in a big old house, party going on, told from the viewpoint of a non-party goer, and they all turned out to be ghosts.
I'm not going to get an answer to this one, am I?