This is one of those rare situations where I actually read the book before I saw the movie. I was in a hotel room in Charleston and I couldn't put the book down. The supposed real life account of what happened to the Lutz family was plenty scary in written form.
The movie follows the book pretty closely. A disturbed boy shotguns his family to death in the middle of the night and, later, the Lutz family moves into the same house where they find hidden rooms, too many flies and an imaginary friend for their daughter who doesn't seem to have everyone's best interest in mind.
The scuzzy, 70s filming really adds to the claustrophobia of this movie. The house seems lived in and the threats seem disturbingly real. Some things don't translate well from the book (one of the most chilling moments in the book featured Kathy Lutz seeing a pair of glowing red eyes outside her daughter's window but it looks kind of goofy on the big screen). There is an escalation of events and even the father seeming to go slowly mad like Jack Nicholson in the Shining. James Brolin is no Jack Nicholson. Rod Steiger does a fine job as a local priest who tries to bless the house. But he is no Max Von Sydow. Margot Kidder got one of her few non-Superman roles here and probably acquits herself best of all the actors involved.
The production value makes this look and feel a little on the cheap side. Which can be helpful in some scenes, but a distraction in others. I would recommend reading the short book and allowing yourself to wonder if it all did really happen.