Excerpts from: "The Man in the Mailbox" interview by Harry Helms. Filmfax, Feb/Mar 2002, Pages 78-79.
The Man in the Mailbox
A.k.a. Dave Ketchum, Get Smart's "Agent 13" Interview by Harry Helms
(Webmasters note: the following are selected excerpts from this rather lengthy interview)
FAX: In 1966, you began appearing as Agent 13 on Get Smart.
KETCHUM: Yes, I replaced Victor French, who had a similar role in the first season as Agent 44. Victor left to do some other acting jobs, so they changed the number and kept the role the same.
FAX: It looked like a lot of the places that Agent 13 was found must have been physically uncomfortable shoots for you. Were they?
KETCHUM: Some were. In my garage, there's this huge picture of the Man in the Golden Helmet, but it's my face on it. Those prop guys are really good. They needed a full size Man in the Golden Helmet picture, only with my face on it so that when Don Adams came up and said [imitates Don Adams' voice] "Thirteen, are you there?" it would slide open, and there I was in the Golden Helmet, just like in the picture.
That was easy. But then they started saying, "Wait a minute, wouldn't it be funny if he was in a sofa?" So there would be a party, everybody would stand up, and I'd be inside the sofa with a girl and a drink. Stuff like that was tricky. And then they put me in a locker at the airport, and then an ice machine, and it kept getting more and more ridiculous. The hardest part for me was when they put Agent 13 in a washing machine. I'm six-foot-two, so I can't fit easily into cramped places, and a washing machine is about as cramped as it gets. They also built an eight-foot tube I got into so I could be spun around in the front of the washing machine. You try remembering your lines while you're spinning around with water and soap squirting in your face! When we did Get Smart Again, I was in a filing cabinet and the had to build a special cabinet for me to squeeze into.
FAX: Was Get Smart a fun set?
KETCHUM: Oh absolutely! It was a lot of fun! We would all laugh at bits like the "cone of silence," because they were so ridiculous. We'd all run in when they were shooting the "cone of silence" because two people doing that was so funny.
FAX: You wrote an episode of Get Smart, didn't you?
KETCHUM: Yes, I wrote the "Classification: Dead" episode in the third season. In fact, I was mainly busy writing most of the time I was working on Get Smart. It didn't take much time to do Agent 13's part in each episode, maybe a morning and a lunch. I wish the time had been available to write more episodes of Get Smart, but I had a lot of other writing commitments then.
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FAX: What do you think accounts for the enduring popularity of Get Smart, especially among younger people who weren't even born or were just toddlers when the series originally aired?
KETCHUM: It's spooky, isn't it? They did a retrospective on the
show at the Museum of History, and we were all there on stage, and there were
two or three hundred people in the audience. We answered questions, 
and
everybody in the audience was only 25 or 30, so they could have only seen the
series in reruns. And the questions they asked! Somebody asked,
"Don, in episode 31, when you had the yellow gun, now why was
that?" And poor Don, he had no clue which episode the guy was referring
to, and doesn't ever remember ever having a yellow gun. How the audience
new such stuff astounded us.
But why do I think the series continues to attract such fans? Get Smart came after the first James Bond movies, so they had a lot of well-known material to do take-offs about. Get Smart was also satire, and nobody does satire on television today. Get Smart did stuff like an episode where they had KAOS take over an entire television network to announce to the world that they had better capitulate, that it was all over, and KAOS had won. But no one saw that broadcast, because it ran opposite a first-run movie on another network! Like I said, no one does that sort of satire on television series anymore. Alan Spencer tried to do it in 1986 with Sledge Hammer!, but I think he was the last one. Get Smart was just a lot different from the sort of comedy you see today on television.
Another factor was Don Adams's voice as Maxwell Smart. He used to do that voice in his nightclub act. I think that voice had a lot to do with it. Somebody told me that he didn't really like to do that voice, but it had a lot to do with the show's success. And the chemistry on the set was important. It was one of those lucky situations where everything works together.
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Wailing Wanda's Bits:
The interview also mentioned a few other noteworthy facts about Mr. 13 which are summarized below:
* Ketchum was born in an elevator. Hmmmm... small places from day one, eh?
* He originally wanted to be an electrical engineer.
* He is a prolific TV writer, having written episodes for: Petticoat Junction, Get Smart, M*A*S*H, Happy Days, Laverne and Shirley, Wonder Woman, The Love Boat, Highway to Heaven, Sledge Hammer!, and MacGyver. Ahhhh.... I do so miss the TV of my childhood....
* Mr. Ketchum was supposed to be in Flying Leathernecks with John Wayne, however, he was activated to serve in the National Guard and had to scrap doing the movie!
Also, as transposed above, Dave Ketchum alludes to why Victor French (the first Agent 44) left G.S. French traded in Get Smart to eventually work in such films as Rio Lobo where he plays John Wayne's nemesis, gets burned, and dies as a result of being used for target practice during a classic showdown scene.