Hmmmm. I looked that up on IMDB and I don't think that's it. Though that is now another movie I'm gonna have to add to the list before the 31st lol. The one I'm thinking of I think involves an adult guy, who I think is a writer, and his son who move into a house. There is some sort of monster/ghost who appears like a monster-fied version of a old-lady/grandma. I think there was a part where they guy calls a friend over because he thinks he has the monster trapped in a closet or something. He ends up "killing" the monster and buries it in his backyard. And like I said, in my OP, I think there was a scene where his son gets pulled into a pitch black void behind the bathroom mirror and the dad has to go after him.