Rep. Donald J. Albosta (D-Mich.), who has been shining the congressional spotlight on possible wrongdoing in the conduct of Ronald Reagan's 1980 presidential campaign, is finding some of the glare reflected on his own record.

At times, Albosta has been accused of making an improper application for a federal loan, helping a government project in which a relative was involved, paying congressional staff members for campaign work, alluding to an opponent's religion as a campaign issue and committing minor violations in reports to the Federal Election Commission.

Albosta said the allegations are groundless and that he suspects that old charges are being circulated by people opposed to his probe of how Reagan aides obtained Carter White House documents in 1980.

"All the issues that have been involved in my campaigns have been aired publicly," Albosta said. "Everything I've ever been involved in has been checked and rechecked. Nothing but allegations have ever appeared, except for a few minor violations with the FEC. I don't see that anything I ever did was unethical . . . . I've got nothing to be ashamed of. If someone can belittle me as chairman of this committee, they undoubtedly will do that. They will try to muddy the water."

Albosta said the past controversies have made him more cautious in handling the debate papers probe. "It makes you a little bit more sensitive when allegations have been made against you and you've faced that with your family," he said. "We shouldn't be reckless in using people's names."

Many of the allegations are old news in Michigan's largely rural 10th Congressional District. where Albosta has gained a reputation as a tough political fighter who often finds himself embroiled in controversy.

Some of them are typical of the kind of charges that surface in hard-fought local races, and they have not stopped Albosta's constituents from reelecting him by comfortable margins.

But Albosta's record has come under increased scrutiny in Washington since Albosta, 57, a farmer, much to the displeasure of the House Democratic leadership, began investigating the debate papers episode.

In 1980, Albosta pushed for a federal loan guarantee for a gasohol plant in Michigan without revealing that his brother-in-law was one of the investors in the project. The Saginaw News reported the connection after Albosta met with Carter administration officials and the Farmers Home Administration agreed to guarantee the $2.9-million loan.

Albosta said he supported the project because it would help local farmers and that he had not known that his brother-in-law had a 6 percent interest in the project. "Nobody ever told me," he said. "When it finally hit the newspapers was when I remember that being brought up. I didn't really see it as a serious thing . . . . If I had a brother-in-law that had Dow Chemical Co. stock, I'd still try to help Dow Chemical Co."

Albosta also ran afoul of the Small Business Administration in 1980. After he received a $99,000 low-interest loan from the SBA for flood damage to his 1,200-acre farm in St. Charles, Mich., the agency found that his application had listed a $17,000 political debt erroneously as a farm loss.

The day he received the SBA loan, Albosta repaid himself for the debt, a personal loan he had made to his unsuccessful campaign for Congress in 1976. He said the mistake on the application "was an inadvertent error on my part" in a bid to disclose all his debts to the SBA. He said he had legally mixed the proceeds of the SBA loan with his farm bank account, but maintained that he did not use any federal money to repay his political debt.

An SBA spokesman said the agency consulted with the Justice Department but decided there was no evidence that Albosta had intentionally filed an erroneous application.

On the FEC violations, Albosta said that minor infractions are common and that he later amended forms that mistakenly failed to report an excessive contribution and about $35,000 in personal loans to his 1980 campaign.

Despite these incidents, Albosta has remained popular by frequently visiting his sprawling district. After Albosta lost the 1976 race, "He never stopped campaigning," said state Rep. Louis Dodak.

Many Michigan officials say Albosta learned how to jump into a highly publicized investigation as a state legislator in 1975, when he bucked the Democratic leadership by launching a one-man environmental probe of PBBs contamination in animal feed, and frequently attacked Republican Gov. William G. Milliken for inaction.

Albosta visited farmers whose cows had died from the toxic fire retardant, and, while state authorities initially denied the problem, an estimated 90 percent of Michigan residents later were found to have PBBs stored in their body fat.

"He knew it was wrong, and Don wasn't going to let it die," said Dell Ormsby, a Michigan roads commissioner.

Roger Tilles, a former legislative aide who later ran unsuccessfully against Albosta, said, "It was clear the issue of PBBs was secondary to the circus he was putting on." He called Albosta "a loose cannon" who "sometimes went beyond the information we gave him and didn't know what he was talking about."

Albosta also made headlines in 1975 when the local press reported that 26 migrant workers were found living on his sugar beet farm in a trailer and a chicken coop.

Albosta said he had allowed nine workers to live in a modern 12-by-60-foot trailer, that the others moved in without permission and were evicted after they ransacked his property.

The PBB dispute helped send Albosta to Congress, but not before a bitter 1978 primary race against Tilles. Albosta repeatedly charged that Tilles, who grew up in New York and later moved to Michigan, was being bankrolled by the Long Island Jewish community.

"I'm not sure his motivation was anti-Semitic, but it certainly came out that way," said Tilles, now a lawyer in Great Neck, N.Y., on Long Island. "He said I was a tool of the Long Island Jewish community, that I was getting out-of-state contributions from the national Jewish community . . . . " He said he became a target of a whispering campaign: "Do you want a Jew in Congress?"

Albosta replied that his administrative assistant and subcommittee staff director are Jewish and that he never meant to focus on his opponent's religion.

While he thought the out-of-state donations were a legitimate issue, Albosta said, "If I had it to do over again, I'd certainly have said it differently. It was said in haste . . . . I would have left the Jewish reference out. I guess everyone makes some mistakes."

In 1980, Albosta complained to Michigan's fair campaign practices committee that his opponent had distorted Albosta's attendance record in the legislature, only to drop the complaint later. "I don't know if either one of us was accurate when it came out in the end," Albosta said.

The opponent, former state senator Dick Allen, said Albosta deliberately filed an unfounded complaint. "He has always pushed ethics to the very limit in his campaigns and sometimes even beyond the limit," Allen said. "He shades the truth, and if he thinks he can get away with it, he'll go with a complete untruth . . . . There is a complete lack of any consistency between the way he runs a campaign and what he's demanding now of Reagan . . . . "

Nevertheless, Allen said, Albosta enjoys a favorable image as a "street fighter" because "people in the district feel he is fighting authority on behalf of the little guy."

During the 1980 race, Albosta removed three of his congressional aides from the House payroll while they campaigned for him in October. After the election, Albosta gave the aides large raises for the next one-month period, in some cases nearly doubling their salaries. "In effect, he was paying them public money for their month of campaigning," said Larry Reed, who raised the issue as Albosta's GOP foe in 1982. Albosta said he took the aides off the payroll to avoid any impropriety, but that they later put in considerable overtime. "When they went back in December and caught up on their work, I felt I had an obligation to pay them . . . if they're willing to work 16 to 18 hours a day," he said.