Mike died Thursday in Los Angeles, according to his 'Somebody' co-star Bridget Everett. The cause of death is unclear.

Everett's remembering Mike as a beloved character actor and devoted husband, saying she "loved Mike the instant I met him. He was so special. Warm, funny, never met a stranger."

Mike's most known for his recurring role as building superintendent Mr. Treeger on "Friends" ... most notably in the season 4 episode, "The One With the Ballroom Dancing," where Joey reluctantly agrees to be his dance partner after Rachel and Monica are threatened with eviction.

Mike appeared on a ton of TV shows over the years ... including "Boston Legal," "Brooklyn Nine-Nine," "Cheers," "Community," "CSI," "Curb Your Enthusiasm," "Entourage," "ER," "Ghost Whisperer," "Glee," "The Goldbergs," "Grey's Anatomy," "Happy Endings," "Medium," "The Mindy Project," "Mob City," "Monk," "Seinfeld," "Shameless," "The Wayans Bros." and "Wonder Years."

He was also a series regular for two seasons of FOX's "The George Carlin Show" and one season of HBO's "Lucky Louie."

Recently, Mike starred in HBO's "Somebody Somewhere" with Everett, playing her character's father, Ed Miller.

Mike, who grew up in Chicago, is survived by his wife, Mary Kathryn. He was 67.