Actress and producer Rita Wilson appears on “Who Do You Think You Are?” (7 p.m., NBC) and traces her family tree by returning to ancestral villages in both Greece and Bulgaria. She learns why her father’s family immigrated to the United States.

An actress since childhood (she appeared in “The Brady Bunch”), Wilson served as a producer of “My Big Fat Greek Wedding,” a film that set all kinds of box-office records in 2002.

Like many immigrant families, Wilson’s parents Americanized their family name. Originally called “Ibrahimoff,” they are said to have plucked “Wilson” from a street sign in Southern California. While it’s purely idle speculation on my part, I think it may be more than coincidence that when Wilson’s husband, Tom Hanks, played a man stranded on a desert island in the 2000 drama “Cast Away,” his only companion was a volleyball named Wilson. Hey, it could have been a Voit!

• Judge Nicastro brims with edicts and advice on “Fairly Legal” (8 p.m., USA). NBC’s tryout for this cable drama last Saturday did not bode well. According to tvbythenumbers.zap2it.com, “Legal” attracted a total of 3.3 million viewers last Friday on USA, but the show’s network showcase the following night was viewed by approximately 2.2 million. This decline speaks volumes about the difficulty of getting folks to watch anything on Saturday night. Or NBC. Or both.

• The guys spend the night locked down in an underground cavern in Nevada on “Ghost Adventures” (8 p.m., Travel).

Tonight’s other highlights

• The CEO of Yankee Candle burns at both ends on “Undercover Boss” (7 p.m., CBS).

• A Mexican restaurant in Philadelphia requires a shakeup on the season finale of “Kitchen Nightmares” (7 p.m., Fox).

• A murder in a lab echoes a mid-century cold case on “CSI: NY” (8 p.m., CBS).

• A little shop of horrors on “Grimm” (8 p.m., NBC).

• Nothing seems familiar any longer on “Fringe” (8 p.m., Fox).

• “Great Performances” (8 p.m., PBS, check local listings) salutes the San Francisco Symphony’s 100th anniversary. Amy Tan hosts. Guests include Itzhak Perlman and Lang Lang.

• A gun returned to a city-sponsored buyback program is linked to a crime on “Blue Bloods” (9 p.m., CBS).