TOM HANKS and Shelley Long are haunted by their dream house in the yuppie horror story "The Money Pit," a hilarious but haphazard renovation comedy.

Hanks, an entertainment lawyer, and Long, a concert violinist, buy a house in the exurbs, a monstrous, million-dollar mansion -- a bargain at only $200,000, but it needs work. Now the sweethearts are both deeply in love and deeply in debt. The house, a malevolent white elephant, begins to show its true colors shortly after they move in.

The circular staircase collapses, the ceiling crumbles, the plumbing rumbles like a submarine sustaining a depth charge. Thick brown goo runs from the faucets to the tub, the wiring self-destructs, and outside, the newly planted birches uproot and topple to the ground.

Director Richard Benjamin successfully pilots Hanks, a Mr. Blanding for the '80s, through a series of elaborate Rube Goldberg pratfalls that shake the rafters and shiver the timbers. These scenes are spoofy, spooky fun, with poltergeist-like effects augmented by Hanks' fine physical sense of humor.

Hanks moves into his castle with the confidence of do-it-yourselfer Harry Homeowner, but he becomes as jumpy as a pretty coed in a slasher film once the house begins to decompose. By the time the tub falls into the living room, he's barking mad.

Long, comically quiet and under-used, is sidetracked in a secondary plot featuring former ballet great Alexander Godunov as her ex-husband, an egomaniacal maestro who tries to win her back. Godunov creates an intriguing character, but that character belongs in another movie. In fact, "The Pit" seems to be three movies ineptly rolled into one.

The sub and the sub-sub plot, something to do with Hanks' dad in Rio, get in the way of the hijinks with the house and the tentatively developed relationship between the stars, who have a cute chemistry that's convincing enough for a good slapstick comedy.

But "The Pit" isn't as funny as it ought to be, for Long and Hanks have a wider comedic range that the unsure Benjamin doesn't exploit. "The Pit," set to open at Christmas, was troubled from the start, and despite six months of remodeling and producer Steven Spielberg's trademark, it still doesn't stand up. Cluttered with characters and plot lines, it is slow to start and stumbles into a mushy, blushing finale.

Writer David Giler can't resist adding a moral to his story -- that love and houses need strong foundations. But it's still just a superficial tale of Brie-eaters' bliss -- a house becomes a home, and a pretty darned good hedge against inflation.