This effect comes from Postal 2, the dark comedy action game in which the player controls the Dude through a week of mundane errands that spiral into chaos. Signing a petition is one of those ordinary tasks, and the brief paper sound was lifted from gameplay and shared on soundboards, where it took on a second life outside the game. It spread because it is instantly recognisable to fans and instantly understandable to everyone else, a tiny piece of bureaucracy that makes an absurd agreement feel official.