The 2016 horror film “Lights Out” is having a resurgence on Netflix, and viewers were so horrified after seeing the movie that they've issued warnings about it on social media.

In the film, a creature that lurks in the dark is the spirit of a tortured woman who terrorizes the children of a friend she received treatment with at a mental health facility.

The horrifying movie zeroes in on the audience's deeply-rooted fears of the dark, and the film uses that anxiety as a cudgel in the face of emotional distress.

Viewers of the film have said on social media not to watch the film in the dark or at night, and some Netflix users even claimed the film kept them up all night in fear.

Before recommending the film, Twitter user @itsme_krrishm wrote “WARNING : If you are a faint-heart person, do not watch it alone.”

@stfuaiyanna tweeted, “I'll never forget the day I first watched that [because] it's the first time I saw somebody be so terrified, [they walked] out [of] a movie theater.”

@saigondjo listed the film as one of two that “traumatized” her, putting the scare-fest on the same level as the incredibly graphic and violent “Megan Is Missing.”

User @aevsify shared his sentiments, promoting “Lights Out” to someone asking for movie recommendations but warning, “It's scary actually, [you] might have a sleepless night.”