Creepy 1970's House Interiors
The set design the director used for the inside of this house really added to the creepy feel of the movie. On the dvd the director explained how he wanted a 70's look for the kitchen,living room,wall paper etc. That narrow hallway leading to the kitchen was very unsettling because you can't tell if somebody is waiting to jump out at you. It reminded me of the kitchen scenes in The Sixth Sense which also used the old house/apartment setting. The director said they found an old empty house and rebuilt the inside for the movie.
...also I couldn't help and think of the classic 1974 TV Movie "Bad Ronald" that also featured a guy living in the walls.