ON Capitol Hill, there's nothing like a good investigation to lift a congressman out of obscurity. A sure-fire way to ignite headlines during a slow Washington summer.

Kefauver. Rodino. Ervin. Albosta. Albosta?

A couple of weeks ago, Rep. Donald J. Albosta (D-Mich.) was just one of the 435, a man whose name was little heard on or off the Hill. That was until the easygoing sugar beet farmer found his issue. And ran with it. Meet Don Albosta and his issue: The Great Debate Book Caper.

"Well, I'm a little overwhelmed, I guess," said the lone legislator who has demanded an investigation into the pilfered Carter papers that apparently were used by Reagan campaign workers in preparation for the 1980 presidential debate.

He walked into his congressional office yesterday after a floor vote and asked the photographer if he could take his jacket off for the picture. "Now that's Don Albosta!" said an aide. There are two framed pictures of Harry S Truman in the office. "He was an honest man . . . first president I ever voted for," Albosta said. Truman is his favorite president, he added.

Albosta was wearing a diamond ring, and rummaging through the hundreds of pages that were released by the Reagan White House this week and are believed to be briefing materials prepared by the Carter campaign.

"In politics, you expect a little of this attention," he said. "But, boy, I'm telling you, it's been something. From those four letters I wrote, I didn't expect it would stretch in to the proportions that it has or generate the attention."

Albosta, 57, got his issue a few weeks back when two eager aides from Albosta's subcommittee--Micah Green and John Fitzgerald--read newspaper accounts of Time magazine reporter Laurence I. Barrett's book "Gambling With History," which said that a Reagan "mole" apparently had "filched" pertinent documents from the Carter camp.

Green and Fitzgerald alerted Albosta, who then shot off letters to the principal White House players--White House Chief of Staff James A. Baker III, White House Communications Director David R. Gergen, OMB Director David A. Stockman, and later, CIA Director William Casey--demanding an explanation.

The responses read like the old Abbott and Costello who's-on-first routine. Suddenly, Albosta was news. He has been swooped upon by all three networks and Cable News Network. He's been interviewed by Newsweek, Time, U.S. News & World Report, The New York Times and USA Today.

Before last week, Albosta had gone a long time between interviews.

"I can assure you I wasn't looking for it," he said of the media attention. "My efforts are sincere. My motives are sincere. They are nonpolitical. Certainly, it may appear to a lot of people that there may be some political motivation." Albosta said he was particularly surprised because he had another issue earlier this year and the media didn't pay much attention.

Albosta heads the House Post Office and Civil Service subcommittee on human resources, which looked into the $50,000 in severance pay received by Attorney General William French Smith before he took office. Ultimately, the subcommittee closed the loophole in the ethics law that had permitted the money to go unreported for 16 months.

On the current issue, in addition to who did what, Albosta volunteered a special concern: shredding. A decidedly Washington phenomenon. Or so he says.

"I understand they're over there sorting through everything they can find, and I would hope they will take me seriously, because I don't want them to destroy the material that may be important to this investigation," he said. "If somebody does that, I think there's an open violation. Under the pressure that this investigation is getting from the media nobody should destroy anything."

What? Is he really worried that they'll destroy the documents?

"I am worried about it, because four shredding machines were put into EPA the Environmental Protection Agency right during the time we cited Anne Gorsuch for contempt of Congress , and tons of material were shredded. It seems to me that may be a way of preventing the public from knowing. The public has a right to know."

In pursuing a full-scale investigation into the papers, Albosta finds himself at odds with his leader, House Speaker Thomas P. (Tip) O'Neill. O'Neill said Tuesday he did not favor a House investigation into the matter and that Carter would have lost the election anyway.

Not the issue, said Albosta. It's the principle. It's the ethics. It's the legality.

"I'm interested in finding out who took them, yes," he said, leaning back in his overstuffed, congressional chair. "I think it's evident that it was a person in the Carter administration. Now it could have been taken because of a love affair. Who knows?

"I'm not trying to go on a witch hunt or trying to do anything that would destroy anyone's reputation. But my responsibilty still remains. Had I got more material and better answers, particularly from Mr. Casey after Mr. Baker pointed the finger directly at him, I would think this investigation would be over by now.

"Mr. Casey simply said, 'I don't remember.' He seemed to have a pretty good memory, if I recall right during his confirmation hearings. One of the senators I was talking to said he remembered him having a very good memory."

Albosta, who is married and has two grown children, came to Congress in 1979 straight from his 1,200-acre Michigan sugar beet, corn and wheat farm. He delivered milk in small towns as a child, worked with crops and did construction work before he started his own farm after World War II. He estimated his farm is worth $1 million.

"Well, there's a lot of peace and quiet out on the farm--there's a lot of hard muscle work that goes with farming, but it isn't anything like this," he said. "Particularly, this kind of investigation. There isn't any way I can stumble. If I do anything wrong, if I fall, I'm going to fall and bruise my head. This is a very important investigation. It's a reflection on the Congress of the United States . . . and on me . . . and what's going to happen to the future of ethics in government."

But however important the investigation, he still savors moments of his Michigan life. "That's where all of this pressure is right now and it's right on me," he said. "The work piles up. And this weekend I'm going home to see what it's like to ride a tractor again. I'll ride the bulldozer. Or something."