1) “Ghosts,” 8 and 8:30 p.m., CBS. Jay’s sister first visited under wobbly circumstances: Fresh from a break-up, she was enamored with a video contact … who turned out to be dead Trevor. Now she’s back at Christmastime (yes, these are reruns), with a guy friend (they’re shown here); Sam, having seen too many holiday films, wants to stir a romance. It’s a funny two-parter that displaces “Young Sheldon” for a week.
2) “What We Do in the Shadows,” 10 p.m., FX, rerunning at 10:35 and 11:10. At times, this clever show switches its focus to Colin, the “energy vampire” (you know the type) who can drain all our enthusiasm toward life. Now he’s running for comptroller, a perfect job for any bureaucrat. There are some great moments here, involving guest roles for Vanessa Bayer, Martha Kelly (“Baskets”) and Hannibal Buress; two sub-plots are merely OK.
3) “So Help Me Todd,” 10 p.m., CBS. Nudged back an hour by a “Price is Right” rerun, this is a clever episode from early in the season. While his old friends prosper, Todd is still living in his sister’s garage, working for his mom. Then he meets the one ex-classmate whose life is worse; he might be able to help the guy avoid prison. This gets too goofy at times, but has sharp dialog and a clever conclusion.
4) “Shark Week,” Discovery. As sleek predators, sharks seem to have few worries. But at 9:01 p.m., we see that some great whites in California might have been defeated by smaller mako sharks; at 10:05, we see that sea snakes may be killing sharks in Australia. There’s also a new hour at 8 (sharks too close to shore in New Zealand) and reruns throughout the day. “Shark Week” concludes Saturday; also “SharkFest” continues on Nat Geo Wild.
5) Movies. Two popular series rerun. The “Hunger Games” films are on AMC at 2, 5, 8 and 10:30 p.m.; the delightful “Back to the Future” trilogy is on Syfy at 3:30, 6:02 and 8:32 p.m. More classics: “Titanic,” 8 p.m. and midnight on the Paramount Network … “The Shining,” 9 p.m., Showtime … and “Jaws,” 11:02 p.m., Syfy.