Dozzie, are you sure it was the Haunted Mansion? I've seen a film about the Tower of Terror, which is good fun if a little cheesy, but re-enacting the story of all the people who disappeared in the lift one mysterious night 40-odd (or how ever many years it was) years ago....
Ding-ding-ding-diiing - ding-ding-ding-diiing
(er, that's the Twilight Zone music by the way, hehehe)