The Haunted Mansion Cheats

Zeke is a skeleton
Hold X + Circle + A + Triangle at the opening sequence, before the legal screen. Release the buttons at the title screen.

Zeke is invisible
Hold X + Square + L1 + R1 at the opening sequence, before the legal screen. Release the buttons at the title screen.

Invincibility
Hold Right, then press Square, Circle(3), Square, Circle, Triangle, X during game play.

Weapon upgrade
Hold Right, then press Square(2), Triangle(2), Circle(3), X during game play.

Level select
Hold Right, then press Circle(2), Square, Triangle(2), Square, Circle, X during gameplay.

Turn lights on and off
Pause the game and highlight Options, then hold L1 + R1 and unpause the game and pause it once more. There will be a new item in the Options screen.