If you watch TV you have probably seen Mike Hagerty once or twice. He pops from time to time when a cop or janitor is in the script. I’d argue his most popular role was Mr. Treeger on Friends, but he’s been doing it since the early 80’s so I could be way off.
He’s been in plenty of movies as well, including Brewster’s Millions, where I spotted him this weekend. Also in his credits is Wayne’s World (nice job, Mike) and Speed 2 (we all make mistakes).