"That was the first time I began to understand, you know, this could be fun," he recalled with a gravelly chuckle. "I must have liked the sound of my own voice."
Other radio gigs followed. After serving as a Navy communications officer during World War II, Wallace returned to his job as a news reporter in Chicago. But he quickly grasped that broadcasting was changing.
"I suddenly realized, 'Hey, you need to be on television. Television is going to happen, and you don't want to get left behind, do you?' "
Wallace started out at a Chicago station, where he did everything from read commercials to act in a police drama, and then did a stint at CBS, where he hosted an interview show with his then-wife, Buff Cobb.
It wasn't until 1956 that Wallace first hit on his unique talent for quizzing newsmakers. At the time, he was working as an anchor for a local New York station and his producer, Ted Yates, suggested they develop a late-night interview program that forced celebrities and politicians to answer tough questions. "Night Beat" was an immediate success, and Wallace found himself getting cheered on by cab drivers as he walked through Manhattan.
He took the program to ABC for a year, where it was called "The Mike Wallace Interview," and then sampled a variety of broadcasting jobs until 1962, when his older son Peter, just 19, died in a hiking accident in Greece. In his grief, Wallace vowed to devote himself solely to journalism.
"I thought to myself, 'Hey, do something that would make Peter proud of you,' " he recalled. " 'C'mon, you can do something more interesting than reading other people's words about peanut butter.' "
In 1963, he returned to CBS as a special correspondent, reporting from Vietnam and then covering the 1968 presidential campaign of Richard Nixon, who asked him to be his White House press secretary.
Wallace declined and instead decided to help launch a new prime-time magazine show being developed by a producer named Don Hewitt. "60 Minutes" premiered in 1968, co-hosted by Harry Reasoner and Wallace.
Hewitt described the pair as "the perfect fit -- the guy you love and the guy you love to hate."
The show took a while to gain a following, but by 1978, "60 Minutes" ranked among the top 10 programs in the country, a position it held for 23 seasons.
A bruising style
Wallace's unapologetic interviewing technique emerged as the program's trademark. He asked Iran's Ayatollah Khomeini about the fact that Egyptian President Anwar Sadat regarded him as "a lunatic" and quizzed Ronald Reagan about the dearth of African Americans on his campaign staff, angering Nancy Reagan, a longtime friend.
"I don't think there would a '60 Minutes' if Don hadn't found Mike," said Jeff Fager, the show's current executive producer. "Mike was never afraid to ask a question, to ask anybody whatever he felt like and say what he thought."
Some of Wallace's stories did more than rankle guests. His 1982 documentary about the efforts of U.S. military leaders to undercount the number of enemy troops in Vietnam led to a libel lawsuit (later withdrawn) and eventually pushed him into such a deep depression that he was hospitalized. A decade later, he sparred with CBS executives over the network's refusal to air an interview with a tobacco whistle-blower.
He's still not shy about voicing his opinions about the goings-on at CBS News. Wallace made headlines in November when he said Dan Rather should have resigned after four newsroom employees were forced out in the wake of CBS' broadcast of a controversial report about President Bush's service in the Texas Air National Guard.
Although he says he has "great respect" for Couric and is curious to see how the news will fare with her at the helm, he's fairly glum about the state of television news as a whole.
"There is so much that is tabloid, so much infotainment," Wallace said. "It's the race to the bottom instead of the race to the top in order to get ratings and make a living."
His colleagues said they're counting on hearing such sharp opinions from Wallace for some time to come.
"He's still going to be around, letting me and everyone else know what he thought of last night's broadcast, and I welcome that -- to a degree," Fager said with a chuckle. "Part of what he's done is to show the way to the other correspondents. We all try to make sure that we don't get too soft, that there's always a little edge, a little skepticism -- that's what he teaches us."