A group of 24 risk-takers on “Wipeout” (ABC at 8 p.m.) tries to win $50,000 by conquering a crazy obstacle course with one particularly challenging spot called the “space pod of doom.”

Syfy had a lot of luck with “Sharknado” earlier this summer, so they stuck with the theme in the original movie “Ghost Shark” (at 9), about a terrifying yet self-explanatory creature that can haunt people by land and by sea.

The detectives on “Motive” (ABC at 9) investigate a case involving family drama when a famous boxing champion is found dead after being stabbed.

Another roommate is evicted on “Big Brother” (CBS at 9) — but possibly only temporarily, because the booted contestant (as well as the last three eliminated people) will compete for the rare chance to get back in the game.

Michael has increased doubts about his mission on “Burn Notice” (USA at 9), but he pushes his conflicting feelings aside to join Sonya on a trip to Mexico to help James finish an important job.

FINALE WATCH: Carol starts dating a handsome singer on the Season 2 finale of the newly renewed “Sullivan & Son” (TBS at 10), which not only makes Owen jealous but jeopardizes the regular bar customers’ chances of winning a karaoke contest.

“The Office” pals Angela Kinsey and Ellie Kemper are contestants on “Hollywood Game Night” (NBC at 10) — which just got picked up for a second season — along with Kal Penn, Max Greenfield, Minnie Driver and “Saturday Night Live’s” Kenan Thompson.

The police go about a routine marijuana bust on “Rookie Blue” (ABC at 10), but it winds up turning into a complicated homicide case as Andy, Nick and Gail try to find the culprit. Meanwhile, the guys — Swarek, Oliver, Chris and Dov — have a male bonding weekend when they head to Oliver’s cabin.

Charlie stumbles upon a secret about Briggs on “Graceland” (USA at 10), and while she works to find out the truth, the FBI targets Briggs as a suspect when Juan goes missing.

One bride thinks her wedding would be a great time to lead her family and friends in a Zumba routine on “Four Weddings” (TLC at 10), while another woman plans a song for her groom.

Tennis champion Serena Williams, comedian Sean Donnelly and the musical group MGMT are on “The Late Show With David Letterman” (CBS at 11:35).

— Emily Yahr