He then performed with the comedy group Contents Under Pressure before joining The Second City's National Touring Company.
Campbell appeared in the Seinfeld episode "The Seven", where he played Ken, the husband of Susan's first cousin, Carrie.
He appeared as oil driller Max Lennert in the film Armageddon, and as the "Man in Hall" in Groundhog Day.
He is presently the primary voice heard on KYOT 95.5 "The Mountain" radio in Phoenix, Arizona.
After securing money through a fundraiser, he underwent surgery in December of that year to remove a tumor that had grown on the bottom of his mouth.