The first filmmaker to try to make the audience believe that there was a problem in the room was William Castle with his film The Tingler in 1959 .
In one scene from this horror film, a creature resembling a large caterpillar slithers into a cinema and terrorizes spectators.
William Castle wanted the real viewers of his film to believe that the creature had also slipped into their cinema.
In the middle of the sequence, he simulates a problem with the reel and, suddenly, the screen goes white and we see the creature crawling over it, as if it were on the projector lens…
The room is then plunged into darkness (in reality, the film simply cuts to black, which plunges the room into darkness) and a comedian declares: “Ladies and gentlemen, don’t panic, but scream as much as you want, because the creature is somewhere in this cinema…”.
In 1959, the trick worked quite well and some spectators seem to have been terrified, if contemporary reviews are to be believed.
Joe Dante will use this trick in 1990, in Gremlins 2 .
While the Gremlins take on a movie theater in the film, the same problems seem to be happening in real life in its movie theater. The reel stalls, the film catches fire and reveals Gremlins in front of the projector.
Note that when Gremlins 2 was released on VHS a year later, Joe Dante adapted this scene to simulate a VCR problem.