They have a captive audience.

“Jersey Shore” stars Nicole “Snooki” Polizzi and Jenni “JWoww” Farley are flooded with fan mail — from inmates in prison.

“I get a lot of jail letters,” Polizzi, 38, told The Post from the “Jersey Shore: Family Vacation” red carpet at Marquee nightclub in Chelsea last week.

“I read them and I show my husband.”

Farley, 41, saves them all — just in case.

“I have a file just in case they get out, because it’s not like they went away for taking a car. We’re talking like quadruple homicide, murder, been away since the ’70s,” she said.

Angelina Pivarnick also receives shocking messages from fans of the original “Jersey Shore,” which ran from 2009 to 2012, and its spinoff, which is airing its ninth and final season on MTV on May 7.

“Some fans have DM’ed me and said, ‘Thank you so much for being yourself and helping me not commit suicide,’ crazy stuff like that,” Pivarnick, 39, said.

“It’s actually touching. I’m like, ‘Oh my God.’ And then I’ll actually DM them back and be like, ‘Your life is worth it. You’re amazing.'”

Mike “The Situation” Sorrentino, who was addicted to painkillers and served prison time for tax evasion, can’t leave his house without being approached.

“If I go out anywhere — it could be five different places — they’ll be at least five different people that come up to me and say, ‘What you’ve done with your life is just beautiful, it’s so very wholesome and it makes me believe in change. I’m so proud of you and I don’t even know you,'” said Sorrentino, 43.

“I get tingles and almost tear up when I go home … It’s so crazy when you walk into most locations and everyone treats you like family.”

Others want the “Jersey Shore” cast to play a pivotal role in the most important days of their lives.

“I get invited a lot to weddings,” Farley said.

“And bridal showers,” Polizzi added.

Vinny Guadagnino, who launched a career as a comedian, said guests at his comedy shows have asked him to star in their gender reveals.

“They’ll be like, ‘Can you just do this video and reveal the gender. We’re going to play it at the party,'” he said.

Paul “Pauly D” DelVecchio recalled a recent request he got before a deejaying gig in Vegas — from a fan who wanted to propose to his girlfriend.

“I got a DM just before my set, and this guy was like, ‘Listen, I want to propose … We met at your set 10 years ago,'” DelVecchio, 45, said.

“I was like, ‘Absolutely.’ We made a whole big thing about it, gave him a microphone to get down one knee. And she said ‘Yes.'”

A-listers have also shown their loyalty to the franchise — which cast members teased will be back despite leaving MTV.

Guadagnino, 38, a regular on Celebrity Row at Madison Square Garden during Knicks games, shared his encounters with an NYC MVP.

“Jalen Brunson is a big fan and he goes to the shore house. The family, they take pictures, they send them to me,” he said.

“And the first time I went to The Garden, he was like, ‘Yo, I’m a big fan.’

“And I’m like, ‘That’s crazy because he’s the king of New York.'”