Lights Out (2:42)
IMDb; shortfil.ms; Vimeo; Wikipedia

This came out in 2013, but I first saw it in 2016, about a week before the theatrical release of a feature film that was based on the short. The premise is simple enough: a woman is heading for bed one night, and turns off the light in the hallway leading to her bedroom. When she does, she sees a shadowy human figure at the far end of the hall. When she turns the light back on, the figure can't be seen. So she flips the light on on and off a few times, and the pattern holds. The last time, the figure is much closer (though its back is turned to her). She leaves the light on, sprints to her bed and hides under the covers. (At this point I'm thinking, "NOPE. No way I'd be sleeping in that house tonight.") Anyway, it continues from there, but that's all I really want to divulge. I'll just say it's scary AF, and if I were particularly fond of being scared, I would have rated the short much higher than I did, because it fucking succeeds. (So why did I even watch it, if I don't like being scared? Because shut up, that's why. Just STFU.)