Long before YouTube transformed pop culture, there was a primitive form of sharing videos using patch cords and two VCRs. Funny clips would spread across the country through underground VHS tape swaps, weakening in quality after multiple generations of dubs.

When he was a freshman in high school, comedy writer Nick Prueher swiped a janitorial training video from the break room at McDonald’s, where he was put on probation for not smiling enough. The tape, which chipperly explained the difference between regular clean and McDonald’s clean, became a living-room hit with his friends.

The novelty of entertaining people with obscure video discoveries never wore off. Now Prueher, a former contributor to “Late Show with David Letterman,” and childhood friend Joe Pickett, a writer for TheOnion, go on the road with the Found Footage Festival, which hits Brookline’s Coolidge Corner Theatre Friday at 9:30 p.m.

The FFF is a blend of humorous footage rescued from the VHS trash heap, live comedy and audience participation. Clips include forgotten infomercials, hokey training videos, offbeat promotional tapes, Saturday morning cartoons that never made it to DVD, celebrity exercise routines and unintentionally funny community access TV programs.

Prueher and Pickett were recently featured in the documentary “Winnebago Man,” which shows them idolizing and hugging the World’s Angriest RV Salesman. Whenever possible, the FFF tries to honor its video subjects in person.

“To us, the unintentional stars are the real celebrities,” Prueher said. “Meeting Julia Roberts would mean nothing to me. But if I were to meet the host of ‘Rock’s Winning Workout,’ I’d be starstruck. My knees would be weak.”

“Rock” is a 1980s Southern California stud who produced his own instructional weightlifting video. He appears in Friday evening’s fitness montage, which will include cardiovascular tips from a feeble Milton Berle and Dolph Lundgren, also known as Soviet boxer Ivan Drago from “Rocky IV.”

“The first videos to wind up at Goodwill are exercise tapes,” Prueher said. “Any celebrity with even the most marginal fame could put one out. They are perfect time capsules of fashion and hairstyles, and overall are pretty goofy. Exercise is not meant to be watched.”

Every clip is culled from VHS and DVD finds from thrift shops, yard sales and even Dumpsters.

Proudly branding themselves as old-school, Prueher and Pickett do not harvest any clips from the Internet. They encourage the audience to donate their favorite tapes in person at live shows.

They also insist the clips are not intended to be mean-spirited.

“Certainly, we’re poking fun at people,” Prueher said. “But it’s more of a celebration. We all have moments we’d like to forget.”

For tickets and more information, go to foundfootagefest.com.