Ghosts” may be the unlikeliest comedy hit in recent CBS history. It’s a single-camera half-hour, adapted from a cult U.K. series, and it’s not from Chuck Lorre. Yet the show, which was just renewed for a second season, has already become a breakout for the Eye network, averaging 8.1 million viewers season-to-date, and improving its time period 15% from last year.

And that’s just on linear, where “Ghosts” is the No. 2 comedy on broadcast, behind only CBS’ “Young Sheldon.” It is also performing well on Paramount Plus, which reports that it’s the No. 1 comedy on the streamer.

“It’s the most pleasant kind of surprise,” says CBS Entertainment president Kelly Kahl. “Material we fell in love with, a pilot we fell in love with. It’s like most hits, nothing screamed that, ‘hey, this is gonna be a breakout hit.’ We hoped for it. We always do. But it was a little bit of a departure from what we normally do. So it’s enormously gratifying to see the show that builds a little each week, increasing audience, the delayed viewing, the streaming numbers, and just the buzz.

“It’s also gratifying to put a big four-quadrant, mass appeal hit back on broadcast TV,” Kahl adds. “It’s fun reading the tweets. We have to take it as a compliment that a lot of people are saying, ‘I can’t believe this show’s on broadcast TV.’ ”

The series, produced by CBS Studios with Lionsgate and BBC Studios’ Los Angeles production arm, stars Rose McIver and Utkarsh Ambudkar as Sam and Jay, who inherit a mansion in the countryside that they plan to turn into a B&B. But when Sam hits her head in an accident, she starts to see the ghosts from different eras who inhabit the manor, including an American Revolutionary War officer (Brandon Scott Jones), a 1920s jazz singer (Danielle Pinnock), a Viking (Devan Chandler Long), the home’s original owner Hetty (Rebecca Wisocky), a Lenape Native American (Román Zaragoza), a hippie (Sheila Carrasco), a 1980s Boy Scout leader (Richie Moriarty) and a late-’90s wolf of Wall Street (Asher Grodman).

Just like the original 2019 BBC series, “Ghosts” takes full advantage of that large ensemble, diving into each character’s backstory and the comedic give-and-take among the spooks, the “living” who can see them and Sam’s husband, who cannot. “We have a lot of very interesting characters and great actors, and that gives us a lot of places to go,” says executive producer Joe Wiseman. “We like to do stories that sometime take place in the past. Sometimes they take place in the present or a mix of the two. It really gives us an opportunity to start digging in deeper.”

CBS chief marketing officer Mike Benson says “Ghosts” is also gaining traction in social media, appealing to a younger audience that isn’t normally known for their love of content on the Eye. “The really interesting that’s happened this year is with ‘Ghosts,’ it’s got a very broad diverse audience where we not only see our core 45-plus CBS audience watching but we also are seeing teens watching,” Benson says. “TikTok is blowing up over ‘Ghosts,’ which you might scratch your head and say ‘really, CBS has a show that’s doing really well on TikTok?'”

“It’s been really gratifying,” says fellow EP Joe Port. “People are telling me that they watch it with their families. That’s awesome; you can get things on different levels.”

In some ways, “Ghosts” is a modern, sophisticated version of the high-concept premises that once dominated sitcoms like “I Dream of Jeannie.” But the producers say the fact that their lead character shares a name with Samantha of “Bewitched” is a coincidence. “Although this is a show about ghosts, we want the stories to be real,” Wiseman says. “Ultimately, the show isn’t about the supernatural: We consider the ghosts as people — they live lives, and we want to tell stories that are relatable to everyone.”

There are ghosts everywhere on “Ghosts,” but don’t expect to see a spinoff just yet. “We’re concentrating on this one right now, but yes, this does seem like something that could be franchised anywhere,” Port says.

But for now, Port, Wiseman and CBS are content for now to focus on planning Season 2, as Sam and Jay prepare to open their B&B, much to the spirits’ chagrin.

“The last five episodes [of Season 1] are building toward the opening of the B&B,” Port says. “In the British version, they actually never opened the B&B so far over three seasons. But, we did as many episodes in one season as they did in three seasons. We have to tell a lot more stories in a year and just because we’re opening the B&B doesn’t mean it’s going to be the guest of the week. There’s going to be a lot of stories that happen when there are no guests there. There’s going to be fits and starts, but we do like the storytelling engine of being able to just have people drop in and without too much trouble on our part for coming up with a reason why they’re there.”

Future episodes will continue to introduce a few more ghosts — it’s a large property, after all — as well as the return of Crash, the headless 1950s ghost seen in the pilot.

As for next season, there’s a chance that “Ghosts” might produce even more than this season’s 18 episodes (limited by COVID contingencies). And Kahl says growing “Ghosts” into an even bigger hit is a priority at the network.

“I think we’ve just scratched the surface in terms of potential audience,” Kahl says.