Viewers might look forward to the annual rite of Halloween-themed programming more were there not plenty of frightening shows on TV the rest of the year. In fact, if you say it just right, the word "Co-STELLLLLLL-oooo" will strike fear into even the most dedicated couch zombie. But a holiday's a holiday, and TV is driven by commercial interests, not aesthetic. That is why we're being treated to a record level of spooky spine-tinglers and macabre mysteries this weekend. And like those bags of candy corn you couldn't give away last year, a lot of what's being tossed our way looks awfully familiar. Tonight Fox re-airs the ninth annual "Treehouse of Horrors" episode of "The Simpsons" (7 p.m. on Channel 4), followed by last year's "Treehouse. " Both episodes also aired last Sunday but were resurrected to help boost Fox's Thursday ratings on this first night of an important Nielsen ratings "sweep." On Friday, fright rockers Kiss - who've now discovered that face paint is a great way to cover those unsightly wrinkles - guest-star on "Millennium" (8 p.m. on Channel 4). On Saturday, the band is back as the musical guest on "MAD TV" at 10:30 p.m. and then as star of its own half-hour live special from Dodger Stadium at 11:30 (also on Channel 4). JoAnne Worley, Gary Owens and other players from the comedy classic "Laugh-In" make a Halloween eve appearance as they sock it to "Sabrina, The Teenage Witch" (8 p.m. on Channel 9). Also on Friday, two shows that are as old as the Butterfinger "fun size" bar return to CBS: "It's the Great Pumpkin, Charlie Brown" and "Garfield's Halloween Adventure" (starting at 7 p.m. on Channel 5.) The Fox Family Channel airs possibly the least commercial Halloween special of the season, "Watts on Your Mind," at 7 a.m. Saturday. This animated 22-minute public service announcement teaches kids to conserve energy by updating the old story of Dr. Frankenstein. The cartoon tries to impart its message and a little cheek at the same time; so when the doctor first tries to bring his monster to life, he knocks out the power in his energy-inefficient house. Hanna-Barbera presents "Scooby-Doo on Zombie Island" at 7 p.m. on Cartoon Network. (If you currently receive Time Warner Cable's basic package only, Cartoon will be moving to Channel 58 on Sunday - maybe sooner if the spirits are favorable.) Also on Saturday, Gary (Kyle Chandler) is kidnapped by would-be witches on "Early Edition" (7 p.m. on Channel 5). Even public TV is getting into the holiday spirit Saturday when the Cincinnati Pops presents "Halloween Spooktacular" at 9 on Channel 19. (What we'd really like to see: a special "Antiques Roadshow" in which persons who have had their once-priceless items refinished are turned into newts.) Matt Frewer, star of the syndicated series "Psi Factor," used to play Max Headroom on TV. But with his Boris Karloff haircut and pallid complexion, he's actually creepier-looking on "Psi Factor," a paranormal anthology airing at 3:35 a.m. Sunday on Channel 9 and 9 p.m. Sunday on Channel 29. (The "psi" refers to the Greek letter for the unknown, not a gauge for tire pressure.) In this week's Halloween-themed episode, guest star Linda Blair plays a mystery writer who has a bad PR week: Her novel becomes the blueprint for a serial murderer, and she suffers an outbreak of multiple personalities. All weekend long there will also be holiday-appropriate movies on American Movie Classics, Comedy Central, the Sci-Fi Channel and Fox Family Channel. Joe Bob Briggs is our guide for five - count 'em, five - "Friday the 13th" movies Saturday night on TNT.

