There is some good news for journalists today. Secretary of State Alexander M. Haig Jr. has moved, in no uncertain terms, to lift what I suggested last week was the slight shadow of the KGB that he had cast on the American press corps by seeming to say that the Soviet Union was manipulating Western media by means of a "disinformation" campaign. u

When the secretary read that suggestion in this space, he said, according to his spokesman, Bill Dyess, "What in the hell is he talking about?" He followed, according to Dyess, with a familiar expletive, which he also applied to the connection made in the offending column between Haig and the authors of a novel called "The Spike" on the same disinformation theme.

I was delighted to get Haig's reaction finally on the record, since his insinuation of American press vulnerabiltiy, made in the course of a briefing of foreign diplomats in February, had cried out for either documentation or disavowal, or so it seemed to me.

The observations cited above, moreover, are not all that now is known of the secretary's views on these matters. Dyess during the week volunteered some of his own observations on his boss. He said that, from his knowledge, Haig neither suggested nor thought that the KGB had any influence at all over any journalist or over any sector of the American press. In private, said Dyess, observing that what Haig says in private is more important than what he says in public, Haig expresses "great admiration" for the American press corps. He believes it to be "the best in the world." It is "self-correcting."

In Haig's mind, Dyess suggested, the difference between misinformation and disinformation -- the latter entailing the more sinister act of a hidden Soviet hand rigging the news -- is "blurred."

I have to interject here that I found this explanation entirely consistent with the rather idiosyncratic way in which Haig often uses words.

As an example of what Haig has called misinformation, Dyess cited a wire service report of late February saying that Salvadoran leftists had executed an American sergeant in combat. It turned out that the sergeant had been in El Salvador on an unrelated OAS mission, had lost his ID card, has been honorably discharged and is now alive and well in an American college.

For a second example, Dyess recalled a news report in which Soviet TV was quoted as saying that the United States has 800 troops in El Salvador. The right number is 54 advisers, plus some Marine embassy guards, he said.

Dyess' third example was a bit juicier: the Flora Lewis New York Times column of March 6, which drew extensively and approvingly on what she described as an official "dissent paper" on El Salvador of Nov. 6, 1980. That paper had been set aside by other journalists, including me, as fishy, and denounced by the State Department as spurious, last year. The day after the Lewis column, The Times published a news story repeating the State Department denunciation, and two days after that Miss Lewis herself acknowledged unequivocally that she had been had.

How strange, I thought, that Dyess, in the course of telling me that Haig did not believe American journalists to be KGB pawns, should call to my attention a case where precisely that possibility was rising to the fore. Was that so?

No, said Dyess, he couldn't go so far as saying that here was an authentic case of Soviet disinformation. He would add only that the source of the "dissent paper" ws suspected to be a particular person who had previously worked for the government. It did not sound to me as though this was Exhibit A.

Meanwhile, Dyess concluded, the press should note how Haig had dealt with the first set of leaks (involving foreign aid and NATO) that had hit the Haig State Department a few weeks ago. Although "almost certainly" the leaks came from outside the department, they raised the question to the secretary of whether he should cut down on the department's contacts with the press. He decided against it, Dyess reported, asking "only that we all speak from the same sheet of music."

Fair enough. I am pleased to relay Haig's insistence, the more credible for being phrased with a pungency remote from his customary bureaucratese, that he does not mean to hang the tag of Soviet "disinformation" on material in the American press that does not reflect the official line.

Again, no one is contending that the American press, in respect to El Salvador or anything else, is as perceptive and truthful as it ought to be. Problems of superficiality and slant remain. But the press is, as Haig said, self-correcting -- though not always fully self-correcting. It has enough burdens without having to cope with vague and unsubstantiated allegations, from any quarter, that it is dangling from a secret Soviet string.