Grandma, I’m full gif is from a South Korean 2006 horror film, APT film.
Watch the movie trailer
This film happens in Se-jin, a Seoul suburb, and basically a young girl moves to a new apartment and she enjoy and spend time looking at the neighbor on the building in front of her window. One day she see all the lights of the neighbors shut down at the same time 9:56 pm. So she start thinking something is going on on that building and it is related to a series of kills in the neighborhood. And she tries to solve the mystery.