TONIGHT'S MUST-SEE

"Elf" (2003), 8 p.m., and "Monk," 10 p.m., both USA Network. OK, the timing is a little off. Christmas is supposed to be after Thanksgiving — we checked. Still, this could be a perfect night of lightweight holiday fun. "Elf" finds the 6-foot-3 Will Ferrell shocked to learn he's not an elf. It works, because Ferrell projects such wide-eyed humanity when leaving the North Pole and heading to the outside world. Jon Favreau directed nimbly and had a great supporting cast. There's also a sweet and charming romance with Zooey Deschanel. This "Monk," is a promising bonus, a new episode at rerun time. Monk is planning a quiet Christmas with Natalie. Then his estranged dad shows up and changes everything. He's played by Dan Hedaya, best known as Nick Tortelli on "Cheers."

OF NOTE

"Ghost Whisperer," 7 p.m., CBS. A musician seems especially bedeviled. It turns out that there are two feuding ghosts at work.

"Battlestar Galactica," 7 p.m., Sci Fi Channel. Two gifted actors go eye-to-eye as Carl Lumbly guests, confronting Edward James Olmos. Three years ago, Lt. Novacek (Lumbly) was believed to be killed in a top-secret assignment from Adama (Olmos). Now he has escaped from the Cylons and is back; this stirs the guilt of Adama and the bitterness of others.

"Men in Trees," 8 p.m., ABC. One of the benefits of a fish-out-of-water series is that it can suddenly reverse things. Marin, who is starting to like small-town Alaska, suddenly returns to Manhattan for the Thanksgiving weekend. Also, Patrick must decide whether to visit there with Annie.

"Close to Home," 8 p.m., CBS. Annabeth may be taking the case too personally, when she pushes to get vengeance for a widowed mom.

"Numb3rs," 9 p.m., CBS. Environmental problems fester at a school, where the illness rate is high and a sinkhole has opened.

Barbara Walters special, 9 p.m., ABC. This is the second half of her special, showing what she views as 30 interview mistakes.