The Nightmares of J.T. Night: She Has a Way of Getting Inside Your Head - The Nightmares of J.T. Night, #3

Rev. Joseph has always gotten along well with his neighbor, Mrs. McGillicudy. When she asks him to help her move one day, he is more than happy to oblige. After the move, he doesn't feel quite right. He is starting to hallucinate things that aren't there. His apartment begins to change, looking more and more like Mrs. McGillicudy's apartment. Sometimes he swears he sees her in his apartment in horrifying ways.
He begins to wonder if he's losing his mind. Come to think of it, she always was a bit odd in a lot of ways. There were, of course, those two really weird incidents in the past. And the other people she had helping her move, something didn't seem quite right about them. He'd chalked it all up to his imagination. But in the end, he is starting to be able to deny, as he's heard several others say before, she really does have a way of getting inside your head.