TONIGHT'S MUST-SEE

"Monk," 9 p.m., USA Network. When a rich guy (Sean Astin) becomes a murder suspect, Monk goes undercover as a butler. He soon finds he loves the job — and his underlings hate him. This episode has moments when it gets too goofy. Overall, however, it's an enjoyable hour.

OF NOTE

"Grey's Anatomy" at 7 p.m. and "Brothers & Sisters" at 8 p.m., both ABC. Here are quick reruns of the most recent episodes. In "Anatomy," rumors are buzzing that the chief will be leaving; also, Bailey proposes a free clinic. In "Brothers," just about everything goes wrong at Nora's 60th birthday party, and her mom (Marion Ross of "Happy Days") spoils the surprise.

"Ghost Whisperer," 7 p.m., CBS. A night of CBS reruns begins with a ghost getting too possessive. He wants Melinda for himself and might hurt her husband. Also, Camryn Manheim plays the mother of a teen who's behaving oddly.

"Close to Home," 8 p.m., CBS. Charged with killing her husband, a woman says he was psychologically abusing their children.

"Las Vegas," 8 p.m., NBC. Sam (Vanessa Marcil) is in trouble in this rerun: Three of her big-money clients skipped without paying. Meanwhile, Ed has a scheme to help a customer impress his wife. And Mary is ready to face her biggest fear with the help of Adam Carolla.

"Law & Order," 9 p.m., NBC. This rerun seems to cast a hesitant eye at NBC's own "To Catch a Predator" news specials: A TV show reveals the names of suspected pedophiles. One of them is promptly killed.

"Numb3rs," 9 p.m., CBS. This is the second half of the story of a killing spree by a teacher and her teen lover. Lou Diamond Phillips guests as a detective working the case.

"Psych," 10 p.m., USA Network. Lassiter is losing confidence so Shawn helps him work a case.