Wayne Knight is the security guard
Dilbert and the security guard at his office building exchange some hostile words and before they know it they have made a bet: They will change jobs for one day. If Dilbert loses, he gives up his house. If the security guard loses he gives up his borrowed car. So, the two set out to switch jobs and Dilbert soon realizes that the job of security is a lot tougher than he thought. When he stumbles on an illegal casino in The Company’s offices after hours, he almost blows it in the “security” department, until he pulls the fire alarm in order to clear the building.