The Haunted Mansion Mystery (1983)

When Angel Wilson and her family move into a spooky old house, their new neighbour Billy informs her the place is haunted by an old miser -- who is rumored to have disappeared with a million dollars in cash. Learning of a secret room in the mansion's basement, the two sleuths make an astonishing discovery -- only to be trapped by a near-fatal cave-in. Now, they'll have to solve the mansion's baffling mystery, or end up missing...just like the miser and his legendary loot!