Following the death of her father, neurotic and spoiled heiress Carrigan Crittenden discovers she has only been left Whipstaff Manor, located in Friendship, Maine, in the will while his vast wealth has gone to several charities. Carrigan and her lawyer and close friend Dibs find a map within the will's papers that tell of an alleged treasure hidden inside the manor, but find the property haunted by a friendly ghost named Casper and his poltergeist uncles the Ghostly Trio. They unsuccessfully attempt to force the ghosts out by way of paranormal experts and a demolitions team. A lonely Casper watches a news report about paranormal therapist James Harvey and is instantly smitten with his teenage daughter, Kat, prompting Casper to inspire Carrigan in summoning Harvey to Whipstaff. Kat dislikes her father's reputation and obsession with contacting the ghost of his late wife, Amelia. The Harveys move into Whipstaff, but Casper's attempt to befriend them fails when his uncles try to torment and scare them away, which eventually fails.
