In fiction, unless a writer's life is violent, cruel, or carnal, most readers will be uninterested by it. Nevertheless, novelists obtain an odd comfort by making their protagonists writers, as though just to write about them corroborated their existence.

The narrator of Wright Morris's 18th novel is a writer whose suburban life has none of the above qualities. He meets two strange men, a plumbler and a housepainter, who live in a Kansas ghost town and wait for a U.F.O. to take them away. The men lure his wife into their weird "space project," and the writer is torn by fears for his wife and his illogical attraction to these oddballs.

Morris writes knowingly of a section of the country and a certain forlornness in men. His favorite locale, the Midwest, provides appropriate metaphors of space and distance, and in the two workmen he indulges his fondness for American eccentrics. The novel's difficulty is that it throws off ideas like sparks - the decline of the Earth, the closing frontier, a writer's problem s with vision and reality - but examines them cursorily. Morris has often been called underrated, but his fiction, though pleasurable and wry, seems limited in means, as if he cannot render his ideas in plot and character.

His one book of short stories, Real Losses, Imaginary Gains, where the form reins his imagination, is masterful. His talent lies in dialogue, for which he has an expert's ear, and in a range of social confrontation from awkward politeness to murderous hostility. The succinct judgments in On Fiction, his essays, show that Morris knows more about his profession than he is able to practice. (Harper & Row, $8.95)

William Logan