In the opening scene of "The Perfect Nanny," an unhappy-looking brunette woman grabs a knife from her kitchen, marches into the bedroom where two people are having sex, and . . . stabs herself in the stomach. It's an obvious twist. Unfortunately, it's the only twist in this dreadful made-for, which is aimed at illiterates. Literally. When the characters aren't thinking aloud, they're reading aloud from whatever book, e-mail or psychiatric case file just happens to be open in front of them. But that's fair, since the filmmakers assume their audience is as stupid as the characters in this movie, which, as the title helpfully telegraphs, is yet another thriller in the venerable "obsessive psycho insinuates herself into an innocent family's life" genre (along the lines "The Single White Female That Attracts The Cradle" or whatever). Since there is no suspense whatsoever in this thriller, its only possible entertainment value is the camp factor, which is, sadly, only moderate. The plot, or excuse for it, centers on Tracy Nelson as the unhappy brunette who, after being released from the psych ward, changes her name and becomes the receptionist for a child care service so she can emulate the heroine of her favorite romance novel, a nanny who marries her employer. Yes, you've already guessed how this sucker is going to end, so you might as well try to enjoy the ride. On the plus side, Katherine Helmond turns in yet another witty performance as yet another horrible old lady, this time the psychonanny's abusive mother. Fans of blood and gore will also appreciate the body count, as the malicious Mary Poppins leaves a trail of victims that would embarrass Ted Bundy. The weak link, as always, is the family that the au parasite stalks, which is so boring that only a psycho would want want to live with them. Widower Bruce Boxleitner is a brilliant neurosurgeon but apparently too stupid to check references, let alone notice that his college-aged daughter (Dana Barron) is actually in her mid-30s. (Sweet "young" Fawn is off to study English Literature at Cambridge in a few months -- it can't be easy to wait fifteen years for your Junior Year Abroad.) The kid who the caretaker is supposed to take care of, ten-year-old Ben, is an easily duped genius (like father, like son). 70s stalwart Susan Blakely, still looking pretty decent in a bathing suit, shows up as Bruce's colleague and potential love interest but doesn't get enough screen time to perk up the proceedings. So you've read that title, which tells you what's going to happen. Watch at your own risk.