THEY'RE OUT THERE. THEY REALLY are. An underground army of anti- metaphor activists is watching, ever alert, ever vigilant, poring over every word written or spoken in America, just waiting for a chance to swoop like hawks on those who dare compare anything to anything else.

Wait a minute. Did I say an underground army? Oh no, here come the letters from veterans' groups. Not to mention people who live in basements. Uh-oh, did I say swoop like hawks? Now I'm gonna catch hell from people who think hawks are just ducky.

Think I'm paranoid? Listen to this:

Back in March, when the Iran- contra scandal was unraveling, some commentators called Ollie North and his cohorts "cowboys." Sen. John Melcher, an anti-metaphor Democrat from Montana, rose in the august upper chamber to denounce this slur. "It is mighty degrading to the cowboy profession to call plotting, peddling global arms dealers 'cowboys,' " he said, before launching into a lengthy defense of the boys in the saddle.

In May, Tom Turner, a member of the Sierra Club Legal Defense Fund, excoriated The Nation magazine for using the phrase "Nicaraguan quagmire." The quagmire is, he wrote, "along with its brethren (swamps, bogs, morasses, fens, muskeg, prairie potholes and so forth), one of our worst-treated minority groups. These boggy places are beautiful . . ."

This past summer, former White House chief of staff Donald Regan told the Iran-contra committees that he thought Ollie North and his arms- trading cronies had been "snookered again by the rug merchants." Needless to say, Allan Furman, the president of the Oriental Rug Retailers of America, could not allow that metaphor to go unchallenged. "It was disparaging against rug merchants wherever they might be," he said. "We're reputable business people."

Even English teachers, who might be expected to appreciate the beleaguered metaphor, have jumped into this crusade. Reporting on a serial killer, The New York Times quoted a psychologist who said, "We expect our killers to look like Frankenstein." That statement moved Joan Baum, a York College professor of English, to fire off an outraged letter to the editor. "As any reader of the novel knows," Baum wrote, "a good case can be made for the great humanity of the so-called monster . . ."

See? They're out there. They really are.

And these nuts won't be happy until they've butchered the language, purged it of poetry and left it as dry and dull as a desert.

Wait a minute. Did I say nuts? Butchered? Dull as a desert? The poor mailman will become a hunchback toting outraged epistles from almond eaters, meat cutters and residents of several southwestern states.

Hold it. Did I say hunchback? As any reader of Victor Hugo's novel knows, a good case can be made . . .