LEAVING HOME By Garrison Keillor Viking. 244 pp. $18.95

WRITERS LIKE Garrison Keillor only come around every 10 or 20 years. When they do they're not immediately recognized for what they really are: social lightning rods. They practice deception.

If you doubt this think about Will Rogers or Robert Benchley, James Thurber or Damon Runyon. Cowboy, actor, cartoonist, sports writer, to mention a few disguises. And all writers to whom Keillor, the laid-back oracle of A Prairie Home Companion, may owe more than a nod.

While most of the world may know Keillor best as Minnesota Public Radio's superstar anchorman-entertainer, he is in fact a dead serious comedic writer (he began at least 15 years ago with The New Yorker) whose true calling is the half-loving, half-satirical enshrinement of Grant Wood's America (Norwegian-Swedish Division). He writes with a purpose. Down with pretense and shopping centers. Up with stoicism and the family. Up with tuna-noodle casserole and sweet corn-on-the-cob.

Garrison Keillor creates a world. And he inhabits it with vital imaginary people who behave according to values Keillor whittles sentences to define for us. His Lake Wobegon, Minnesota, is as palpable as William Faulkner's Yoknapatawpha County, Mississippi -- in most ways its antithesis even though sensible people don't compare the merits of comedy and tragedy.

True, Garrison Keillor's probably not Nobel Prize-bound. But eyewitnesses say some of his 3 million loyalists wept when he left public radio and the Disney channel for Denmark last June. His fictional history of Lake Wobegon (Lake Wobegon Days, 1985) sold 3.9 million copies, making him a multimillionaire and entitling him to act like Henry Kissinger in interviews. Furthermore, Ronald Reagan tuned him in nearly every Saturday evening. Garrison Keillor has touched something important, perhaps even deep, in the psyche of our republic.

WHAT IT is lies near the center of these 36 stories, all originally delivered (without the dirty words, I assume) as monologues by Keillor during his 13 years on A Prairie Home Companion. They tell of a much easier time and simpler place than ours, when the only drug to worry about was alcohol and the only crook in town was a stranger passing through too fast in a Lincoln Continental ("The Speeding Ticket") who got even by selling the cops $20 bottles of tonic to reverse the effects of aging. It's a time and a place secure against the ravages of marketing, high technology, and affluence. No computers, designer jeans or Japanese cars. Instead, party-line telephones, feed-company caps and pick-up trucks with cracked radiators in mid-winter ("Post Office"), proving that in a small town "you know so much about other people . . . you have to figure they know at least as much about you." While neighbors watch one another and Pastor Ingqvist or Father Emil may have to consider the devil's doing, the social and political atrocities of our nonfiction world -- abused children, homeless old men and women, AIDS and Lebanon -- don't intrude on Lake Wobegon. Nostalgia everywhere. Maybe time has stopped.

Instead of transporting us to gloom, the favored action of young fiction writers, Keillor tells us about the waitress at the Chatterbox Cafe who after 13 years finally takes her mother's advice to "do something with yourself" ("Darlene Makes a Move"), or about the day 24 Lutheran ministers on a tour entitled '"meeting the Pastoral Needs of rural America" all board Wally's new boat and tip it over trying to put out a fire ("Pontoon Boat"), or about the ingenious bourbon-laced mincemeat pie Daryl Tollerud makes after mistakenly throwing his wife's filling in the garbage ("Christmas Dinner").

But Keillor's deceptive, remember? These three stories are also about psychological persecution and the fear of change, the provincial arrogance of city folk, and the tyranny practiced by aging parents on adult children. He usually starts telling one story, moves into a second, and shifts to a third which ends in a surprise or a blush of sentimentality, or closes with a puzzlement or a quiet rage. "Out in the Cold" isn't about the bishop's visit to Lake Wobegon to discuss a successor for Father Emil, pastor of Our Lady of Perpetual Responsibility, who has cancer. It's about Keillor's idea of sin. The bishop refuses to stop his chauffeur-driven Cadillac on the way back to Brainerd to pick up an old farmer freezing on a back road.

I didn't much like Keillor on the radio. He seemed to be faking my childhood. But as a writer, he's all right, knowing how to choose words and close paragraphs. He's a bit sloppy with love and holding little kids' hands. It's also boring to begin every story with, "It has been a quiet week in Lake Wobegon." (Everywhere.) Okay for radio. Pointless in a book.

It seemed disingenuous for Keillor to talk about his "failures" when he closed down A Prairie Home Companion. But it's wholly admirable to read in his introduction to Leaving Home that he gave up the show because he and it were becoming part of the gaseous bamboozlement of fame, the very stuff he was writing to deflate. "I felt watched. Felt mistaken for somebody else. It dawned on me that life might be better elsewhere." He tries to live as he writes.

Reading Garrison Keillor the demons shrink in size. His characters don't lead lives of quiet desperation. They don't live in paradise either. They live in another kind of metaphor for our own lives, with the terrors reduced mostly to getting along with your mate, raising the kids, resisting progress and guarding against sham, and accepting the ultimate fate -- life's end. We can make it on these terms.

Webster Schott lives and writes in Lake Quivira, Kansas.