TV stars from several generations get a workout tonight on a couple of cable movies. Best known for playing John-Boy Walton in his youth, Richard Thomas stars in “Wild Hearts” (8 p.m. today, Hallmark) as Bob, a Los Angeles policeman who makes a radical midlife U-turn.

People in Hallmark movies have all the luck. One minute Bob is picking up his surly teenage daughter, Madison (Hallee Hirsh), from her posse of bored skateboarding pals, and the next he discovers that his estranged father has died and has left him an expansive horse ranch. Up-talking Madison worries about the lack of malls in rodeo country, but even she seems dazzled by the new spread. “This looks like something out of a Western movie,” observes Madison as if speaking for us all.

Within moments she’s horse crazy, and widowed Bob has caught sight of Emily (Nancy McKeon), the fetching local vet.

You don’t need a crystal ball to figure out what happens between the widower and the horse doctor. A nasty local developer with his eyes on the ranch adds some complications to this horse opera, and Bob learns some truths about his bad relationship with his father. But the emphasis remains on father-daughter bonding and all that scenery.

¢ Morning TV alert! In anticipation of baseball’s All-Star Game, GSN dedicates this morning to vintage episodes of “What’s My Line?” featuring appearances by baseball legends, including Ted Williams (8 a.m. today, GSN), Joe DiMaggio (8:30 a.m.), Jackie Robinson (9 a.m.) and Willie Mays (9:30 a.m.).

¢ “True Caribbean Pirates” (7 p.m. Sunday, History) recalls the history behind the movie-generating legends. After Christopher Columbus claimed the West Indies for Spain in 1492, the traffic in gold between the New World and the Old World drew the attention of rival kingdoms that hired privateers to pinch some of the Iberia-bound loot.

Over the centuries, the relationship between sea-going scalawags and colonial officials grew. The royal governor of Jamaica hired Sir Henry Morgan to plunder nearby Spanish possessions and raid shipping lanes. “True” chronicles Morgan as well as his other violent raiders, male and female, including Calico Jack, Anne Bonny and Mary Read.

Today’s highlights

¢ Scheduled on “48 Hours Mystery” (7 p.m., CBS): A morgue assistant becomes a target of terror.

¢ Scheduled on “Dateline” (7 p.m., NBC): A murder in Memphis.

Sunday’s highlights

¢ A fisherman catches a break on “Extreme Makeover: Home Edition” (7 p.m., ABC).

¢ A journalist (Bruce Greenwood) changes priorities after his wife (Madeleine Stowe) is diagnosed with Parkinson’s disease in the 2005 drama “Saving Milly” (8 p.m., CBS). Based on a true story and a book by columnist Morton Kondracke.

¢ Charlie Murphy and Donnell Rawlings host “Chappelle’s Show: The Lost Episodes” (8 p.m., Comedy Central).