David Schwimmer once served Sir Rod Stewart with divorce papers

Appearing on 'The Late Show', he told host Stephen Colbert: "Once, oh man, thank goodness I've never run into him since, but I served Rod Stewart.

"I don't even know if he knows. I don't think he knows."

The 58-year-old 'Goosebumps' star explained how he got the job through his mother, Arlene.

He said: "One summer after my freshman year in college, I was just looking for work, and my mom said, 'Well, you can be a process server for me.'

"My mom was a divorce lawyer, and I was the guy who would pop out of the bushes and serve you divorce papers."

He joked the job made him feel like James Bond, as he'd get "tipped off" on where he might need to go to find people who needed serving their papers.

Late night talk show host Stephen joked that Sir Rod definitely "knows now" about David's job.

He quipped: "Change your locks, man. He's vengeful. You could theoretically run into Rod Stewart sometime and now he knows to punch you."

David didn't reveal who was divorcing the 'Maggie May' singer, now 80, at the time.

However, Sir Rod did get divorced from first wife Alana Stewart in 1984, the same year David celebrated his 18th birthday.

A decade later, David had his breakthrough role as Ross Geller in 'Friends', and he recently recalled a "genuinely frightening" moment after co-star Matt LeBlanc - who played Joey Tribbiani - dislocated his shoulder on set.

He told Entertainment Weekly: "During the live taping of the show, [Matt LeBlanc] is supposed to do a kind of a pratfall, and he actually dislocated his shoulder.

"He went totally white, and he stood up, and I could see his shoulder was out. He looked like he was going to pass out.

"[I remember] immediately turning to the camera like, 'Cut, cut, cut.' That was genuinely frightening."