It can be used as a comedic tool like in the case of a teenage girl and her date when they are arriving home and a parent flashes the light to reveal that they are watching. It can also be used as a plot builder or for suspense. In one of my favorite shows, Chuck, the main character (Chuck, of course) was trying to propose to his girl. Everytime he tried, something happened, from a person walking in the room to being led off in handcuffs (the shows theme is spies from the CIA and NSA). Best of luck to you.
