Flashlight

Flashlight is an item used by Luigi in Luigi's Mansion. When Luigi first entered the mansion, he was only armed with the flashlight. When Luigi progressed in the game, however, he could use it to stun ghosts. All he had to do was hold down the B button, and let it go to release a flash of light.

The Flashlight, under stylus control, was also used to stun Boos in the Super Mario 64 DS minigame Hide and Boo Seek, which was also included in New Super Mario Bros.

The Flashlight is an inventory item in the book Flown the Koopa. If they have it, Mario and Luigi use it to explore the basement of Magikoopa's fortress, but the batteries die, leaving them at the mercy of a pack of Mega Moles.