"I am praying for his family during this time of distress and for his safe return," Cameron says in a statement. "Andrew, if you’re reading this, please call me."
Koenig, 41, who starred as Boner on the show, never returned to his Los Angeles home as scheduled on Feb. 14 after a trip to Canada. His father described him as sounding "despondent" the last time they spoke.
Cameron, who played Koenig's neighbor Mike on the hit '80s show, says, "Mike and Boner could always work things out when they put their minds to it. I'm praying for you, pal. Hope to hear from you soon."