Just added a Pandora's Cardboard Box to my game Coin-Op Vice. It works quite simply: there's a 50% chance it'll hit and take away a life, and a 50% chance it'll give you a new cartridge. You can adjust the percentages in your favor by leveling up the Trap Detector skill.
Wishlist the game!
https://store.steampowered.com/app/2722640/CoinOp_Vice/