A sheet of mono-yellow wallpaper, an empty office hallway, the hum of fluorescent lights: In a certain corner of the internet, that mundane image has been short

The movie’s massive opening weekend haul is the largest ever for an original horror film.

AP:Young audiences turned out in droves to movie theatres around the country this weekend for a small-budget horror from a 20-year-old first-time filmmaker that began on the…