The Supreme Court ruled yesterday that police need a search warrant to enter one person's home to look for another person wanted for a crime.

The 7-to-2 ruling still allows authorities with an arrest warrant to force their way into the suspects own home. But for the first time, the court said that the homes of others, friends or relatives who might be hiding the suspect, are off-limits without a search warrant.

The decision is thus an important extension of the right to privacy in the home. Authorities, except when they are in "hot pursuit," will have to go to a judge or magistrate and explain the reasons for wanting the search before getting a warrant.

The decision would clearly prohibit the sort of warrantless clearly prohibit the sort of warrantless raid that took place in Alexandria during the nationwide hunt for heiress Patty Hearst in 1975. Riot-gun-equipped FBI agents forced their way into a woman's apartment without a search warrant after receiving an anonymous tip that the woman's roommate looked like Hearst. The woman tried unsuccessfully to sue the government for that incident.

It could also help resolve a current damages suit brought by the American Civil Liberties Union on behalf of two Fairfax County families whose homes were subjected to a warrantless search by police looking for a relative in connection with a divorce case.

The opinion continues one of the few Burger court trends that has unequivocally delighted civil libertarians: the respect for the sanctity of the home. It upset dissenting Justices William H. Rehnquist and Byron R. White, however, who said it will "undoubtedly" let some fugitives escape justice and create uncertainties for police in the field.

Justice Thurgood Marshall, for the majority, acknowledged the "additional burden" on police. But it is "minimal," he said, while "the right protected, that of presumptively innocent people to be secure in their homes from unjustified, forcible intrusions by the government, is weighty."

Yesterday's case, Stegald vs. U.S., originated with a Drug Enforcement Administration search for Ricky Lyons, who was wanted on drug charges. In January, 1978, a confidential informant gave agents a telephone number in the Atlanta area where they might be able to find Lyons. After determining the address involved, 12 officers carrying an arrest warrant for Lyons, but no search warrant for the home, drew their guns and went in to the house of Gary Steagald.

They did not find Lyons there. But they allegedly found 43 pounds of cocaine. Steagald was arrested and indicted and convicted on federal drug charges, with lower courts refusing to throw out the conviction because of the warrantless search. Appeals courts have been sharply divided on the need for a search warrant.

Yesterday, the Supreme Court reversed the conviction. Marshall's majority opinion noted that last year the court had prohibited police from entering a suspect's home without an arrest warrant except in hot pursuit. In addition, police may not rummage through a suspect's home looking for evidence without a search warrant.

Extending that right to third parties who are not suspected of anything is the nexft logical step, Marshall said. "A contrary conclusion," he wrote, ". . . would create a significant potential for abuse. Armed solely with an arrest warrant for a single person, the police could search all the homes of that individuals's friends and acquaintances."

In other action yesterday:

In an opinion confused by the absence of a clear majority, the court said that defendants do not have an absolute right to have potential jurors in a trial questioned about whether they are racially prejudiced. The justices thus eliminated what many considered a flat rule that a judge had to ask such a question if the defendant requested it.

The opinion stemmed from the 1979 California conviction on immigration violations of Humberto Rosales-Lopez, who is Mexican descent.

When selecting jurors, defendants and prosecutors submit questions designed to screen out as many hostile jurors as they can. Rosales-Lopez wanted to ask the panel whether "race or Mexican descent" might be a factor in judging his guilt or innocence. He was concerned about a possible negatived reaction to the fact that he lived with a white woman, who was also involved in the case. The judge refused tro ask the question, though he did permit an inquiry as to attitudes towards "the alien problem."

Rosales-Lopez appealed unsuccessfully, citing a 1931 Supreme Court opinion that appeared to require such questions at a defendant's request. Yesterday, however, six justices said there is no absolute requirement. Four justices, led by White, said it must be asked when the crime is violent and when race could clearly affect a verdict, as when the defendant and the victim are members of different racial groups.

Two justices, Rehnquist and Chief Justice Warren Burger, said the decision should be left to each trial judge.

And three others, John Paul Stevens, with Marshall and William Brennan, dissented, saying the racial question should be asked whenever a defendant requests it.

The court settled a multimillion-dollar dispute over how to disburse revenues from oil underlying national wildlife ranges in Alaska. Two federal laws were in conflict in the case (Watt vs. Alaska). One -- the court settled on yesterday -- allocated 90 per cent of the money to the state and 10 per cent to the federal government. The other granted 25 per cent to the county or borough where the range is located, to be used for schools and other public services, and 75 per cent to the Interior Department to help pay the costs of wildlife preservation.

The immediate controversy involved the Kenai National Moose Range, which has already produced $57 million in lease revenues. But at least 17 other Alaskan ranges will be affected by the decision, in which Alaska was the big winner.