Another scene in the two-week-old bugging burlesque at the headquarters of the Republican National Committee here was played out yesterday as D.C. police charged four private investigators involved in the case with operating without licenses.

The charges -- all misdemeanors carrying penalties of up to $300 or 90 days in jail -- stem from the investigators' attempts to study mysterious wires and an apparent magnetic field inside the Capitol Hill office of party cochairman Mary Crisp.

Assistant Police chief William Dixon said yesterday that the charges were an unexpected "spinoff" on the department's continuing investigation into the case, which has become a source of irritation and embarrassment among Repupblican officials and police.

The police took over the investigation after three days of inconclusive work by the private detectives, who had been called in by Crisp and other party officials after she became suspicious that her office had been bugged. Crisp has drawn the fire of some in the party for her support of the Equal Rights Amendment and her encouragement of presidential candidate John Anderson.

Police say they have found no evidence of bugging in the office; their initial report said the mysterious wires simply led to a piped-in music system. But an official of the music firm contradicted that, saying the wires didn't belong to his company. The police investigation is continuing with lab tests and interviews of GOP officials.

The magentic field that private investigators said they had found around Crisp's desk has since vanished.

Those charged with operatiang without licenses were:

Richard Govignon, a Baltimore-based investigator, who made the first investigation of Crisp's office in June 18 at her request.

George Lesser, with the Interstate Bureau of Investigation Inc. of Baltimore, who Govignon brought into the investigation.

Robert Shortley and E. K. Kramer of Interspect, a Washington firm who were asked by other Republican officials to make an "elelctronic sweep" of the offices.

Govignon was also charged with failure to maintain a business premise in the District and operating a business as an unlicensed private investigator. Shortley, who owns Interspect, was also charged with operating an unlicensed private detective business. All the charges carry the same penalty.

In addition, Marshall M. Meyer, owner of the Interstate Bureau of Investigation was charged with permitting an unlicenses employe (Lesser) to perform investigations.

None of the men was available for comment yesterday.

"What makes it binding on these investigators to get licneses is that they are for hire," said Dixon.

Under District law, private investigators must undergo a police security check and pay an annual licensing fee of $158.

Dixon said that during the police department's investigation, officers were reading the investigators' reports and someone asked if the men were licensed. When the department checked city records, it found that they were not.

Dixon said that if the men post $50 bonds that they are willing to forfeit they will not be prosecuted further. "But they still have to get licenses" if they want to operate in the District.

Police have been hampered in their attempts to interview GOP officials because many of them have left town for the party's national convention in Detroit, Dixon said. He said he expected that the investigation would be completed by the end of the month.

"I'll bet they're glad to get out of this," one police officer said of the absent GOP officials. "It's been a comedy of errors and I'm sure a lot of them would like to forget it happened. So would we."