Match Game - S11-E18
Revealing mistake: 4 minutes into the show, Frasier gets off the elevator and goes to an office door with keys to open it, he tries the keys and they don't work. He realizes he missed his floor. A woman opens the door and they start talking about a dating service which he says he doesn't need, and he pushes the elevator down button, which lights up. The doors open and a man gets off. It's going up, which he finds out from an ex-girlfriend on the elevator. The down button light goes out before he gets on to go up with her. The light should only have gone off on the way back down.
Answer: It equals the record of James Arness of "Gunsmoke" for the actor who's played the same part on TV NOT in a soap opera. If you include soaps there are two main contenders - William Roache, who's been playing Ken Barlow in "Coronation Street" in the UK since 1960. Don Hastings has been playing Robert Hughes in US soap "As the World Turns" since 1960 as well.