The Backrooms

If you're not careful and no-clip out of reality in the wrong areas, you'll end up in the backrooms, where it's nothing but the stink of moist carpet, the madness of mono-yellow, and endless background noise of fluorescent lights at maximum hum-buzz, and approximately six hindered million square miles of randomly segmented empty rooms to be trapped in.

Based off of the creepypasta and game by puppet combo