Mom and dad had moved in to their new house with their two daughters. Their room is upstairs, just off the staircase, with a little closet on the other side. One of the daughters has an imaginary friend there, and it turns out to be a ghost/demon of some sort, and the dad sets up cameras to try and catch sight of this thing. There is a scene of it making a mess in the kitchen during the night. The dad is reviewing the tapes in his studio constantly, and the wife is incredulous that anything is happening. The whole movie just drags on.
This sounds like Paranormal Activity 3 (2011).
Here is a snapshot of the little girl talking to her "imaginary friend." If I remember correctly, there is a little closet right in-front of where she is standing.