SO, WHAT HAPPENS when a G-rated guy goes “blue”? Bob Saget will host “Videos After Dark” (10 p.m., ABC, TV-14), beginning tonight. The longtime TV personality will comment upon and introduce clips a tad more grownup and edgier than the standard “America’s Favorite Home Videos” fare.

At a time when broadcasters can’t mine enough ’80s and ’90s nostalgia, Saget is a living touchstone for viewers in their 30s and 40s. Not only did he host “AFHV,” he was the dad on “Full House.”

Netflix has already cast him in its reboot “Fuller House,” so it follows that ABC let him play in the “Dark.”

This hosting gig also conforms to Saget’s career decision to pursue more adult-related standup comedy while still appearing in relatively family-friendly fare like the WB’s “Raising Dad,” or his voice work on CBS’s “How I Met Your Mother.”

Nothing announced Saget’s move into four-letter-word territory like his appearance in the 2005 documentary “The Aristocrats,” featuring dozens of comedians telling, retelling and embroidering what is considered to be one of history’s filthiest jokes.

ABC seems confident that Saget’s original audience will follow him to the hour before late-night.

“After Dark” follows a well-trod TV tradition. For decades, viewers have warmed to clips of “The Newlywed Game” contestants or “Hollywood Squares” talent offering wildly inappropriate remarks. This genre dates back to well before the videocassette era, when “The Tonight Show” recycled clips of Ed Ames’ wayward hatchet. It’s impossible to calculate how much money has been coined repackaging old Dean Martin roasts, in which that entertainer and a raft of A-list talent tip-toed right up to the line separating the “naughty” from the profane.

The transition from “clean” TV comedy to rougher stuff has not always gone smoothly. Soon after the movie industry began slapping content ratings on films, Alan Funt, host of the beloved “Candid Camera” series, made a 1970 hidden-camera comedy film called “What Do You Say to a Naked Lady?” It received an X-rating. That was a bridge too far for viewers who held Funt right up there with Art Linkletter and Mike Douglas.

At least Funt remained behind the camera. Paul Reubens’ (“Pee-Wee’s Playhouse”) experience watching X-rated fare would earn him a mug shot.

If anyone can navigate this terrain, it’s Bob Saget. He’s been doing this for a long time.

• “MasterChef” (8 p.m., Fox, TV-PG) enters its 16th season, with 24 junior chefs with their eyes on the prize.

• Anybody who thinks that the notion of an eager press falling for stories began with the Jussie Smollett (“Empire”) incident should revisit the great 1937 screwball comedy “Nothing Sacred” (10 p.m., TCM). Carole Lombard stars as a sickly Vermont maid at the center of a cynical newspaperman’s (Fredric March) publicity stunt.

Directed by William Wellman and produced by David O. Selznick, its sophisticated story and witty dialogue hold up after more than 80 years. Perhaps because a writing team including Ring Lardner Jr., Budd Schulberg, Dorothy Parker, Sidney Howard, Moss Hart, George S. Kaufman and Robert Carson contributed to the script.

Speaking of old material that holds up, March also stars in the original 1937 version of “A Star Is Born” (8 p.m., TCM), remade for the fourth time in 2018.

• TV-themed DVDs available today include the Acorn Swedish import “The Simple Heist.”

Other highlights

• Fred Armisen, Christopher Walken and musician Carly Simon climb their family trees on “Finding Your Roots With Henry Louis Gates” (8 p.m., PBS, r, TV-PG, check local listings).

• The kidnapping of an heiress smells like a publicity stunt on “FBI” (9 p.m., CBS, TV-14).

• Colton discusses his “journey” amidst rose petals on the season finale of “The Bachelor” (8 p.m., ABC, TV-14).

• Kate’s pregnancy keeps the family on tenterhooks on “This Is Us” (9 p.m., NBC, TV-14).

• A terrorist has it out for Hannah on “NCIS: New Orleans” (10 p.m., CBS, TV-14).

• A snowpocalypse creates special challenges on “New Amsterdam” (10 p.m., NBC, TV-14).

Cult choice

A special effects artist on films including “Star Wars,” “Raiders of the Lost Ark” and “Willow,” Joe Johnston made his directorial debut with the 1989 Disney sci-fi comedy “Honey, I Shrunk the Kids” (8:25 p.m., HBO Family), starring Rick Moranis.

Series notes

Undercover underwater on “NCIS” (8 p.m., CBS, TV-PG) ... Volunteers vie for prizes on “Ellen’s Game of Games” (8 p.m., NBC, TV-PG) ... It’s hard to keep Cicada down on “The Flash” (8 p.m., CW, TV-PG) ... Isobel’s fate remains uncertain on “Roswell, New Mexico” (9 p.m., CW, TV-14).

Late night

Timothy Olyphant appears on “Conan” (11 p.m., TBS) ... John Turturro, Andrew Rannells and Robyn are booked on “The Late Show With Stephen Colbert” (11:35 p.m., CBS) ... Jimmy Fallon welcomes Keira Knightley, Jon Glaser and the Chainsmokers featuring 5 Seconds of Summer to “The Tonight Show” (11:35 p.m., NBC) ... Paul Giamatti, Jessica Walter and Allison Miller visit “Late Night With Seth Meyers” (12:35 a.m., NBC).