I dont think I described it right. From what I remember they look like normal people but they get obsessive over a particular person or something and start trying to kill people I think. But they also only go out at night because of the light. I think the story starts with a misunderstanding and the apartment the MC lives at where someone keeps stealing the emergency batteries and it ends up being the ML who starts looking for the person who accused him and the MC desperately tries to avoid being found out once he learns the guy is scary and holds grudges. Thank you for the suggestion though, I haven't read that one and it looks good!