The head of a detective firm that found suspicious wires at the Republican National Committee office said yesterday that the wires led to a small jack that could have been attached to a listening device. But several electronics speciaalists interviewed said the reported evidence of a possible bugging there was still inconclusive.

The jack was at the end of a twin strand of electrical wire tucked above a false ceiling in the fourth-floor office of Republican National Committee Cochairman Mary Crisp, according to Marshall M. Meyer, president of the interstate Bureau of Investigation, Inc. of Baltimore.

Meyer emphasized, however, that the jack itself was not capable of picking up any sound and was not hooked up to anything else.

Meyer's description yesterday of what was found during an inspection of Crisp's office at 310 First St. SE differs from the initial account of another investigator who said the wires ended in a splice "that didn't connect with anything."

Meyer cautioned, however, that the evidence was still too slim to show that any easesdropping was actually carried out.

Several experts interviewed yesterday agreed that the signs of possible bugging were inconclusive, but observed that they were also consistent with several techniques of electronic surveillance.

A former Army counterintelligence officer, Richard E. Govignon, and a specialist from Meyer's firm, George Lesser, discovered the white electrical wire Wednesday afternoon in a sweep of Crisp's office. Using special equipment, they also found a measurable electromagnetic field to the left of Crisp's desk.

The experts cautioned that the findings could have totally logical explanations that have nothing to do with spying.

Electromagnetic fields, for example, are created by almost any electrical device or motor. It is even possible that passing Metro subway trains created measureable fields in Crisp's office, which is located virtually on top of the subway's Blue-Orange line, just across the street from the entrance to the Capitol South station.

Voicing similar caution, the FBI said yesterday it had not entered the case because there was still "no hard evidence" of any wiretapping or any other kind of electronic surveillance.

FBI spokesman Roger Young said the bureau was still awaiting the results of a more thorough check of the entire RNC suite which GOP officials ordered last evening.

"We'll receive the results of that," Young said. "If it should show hard evidence of wiretapping, we'll enter the case."

"When I say wiretapping," he added, "I'm talking about the ability to intercept wire communications and oral communications indirectly. It's possible to intercept conversations without linkage to a telephone."

In addition to the possibility of a listening device that could have been attached to the jack on the electrical wire, experts said the wire could have been connected instead either to a transmitter that was subsequently removed or tied in some way to a phone line.

However, they said the type of wire used --normal electrical lighting fixture wire -- would not be the first choice for an expert seeking the best possible transmission, if a transmission were involved. A different type of cable offering protection against possible outside radio interference would be preferred, they said.

Govingnon told The Washington Post Friday that he had been asked to conduct a sweep only of Crisp's office. He said he found the wire stretching "the full length of her office" -- from close to the hallway at one end to another side of the room.

"It looked like it (the wire) came from the office of one of her aides" adjoining Crisp's, Govingnon said.

Elaborating on that account, Meyer said Govingnon requested the help of his firm. "I supplied Mr. Lesser to him," Meyer said. "Govingnon was strictly an observer. I don't believe he's technically qualified to utilize the equipment that was used."

Govingnon, who is security director for the Commercial Credit Corp. in Maryland, could not be reached for comment yesterday. Crisp said she hired him after consulting with "someone I respect who is involved in intelligence."

According to Army officials, Govignon joined the Army as a second lieutenant in 1968 and was assigned to the 109th Military Intelligence Group in Baltimore. In 1971-72, he served in Vietnam as a counterintelligence officer with the 57th Military Intelligence Detachment. He was promoted to captain and awarded the Bronze Star and several servace medals before moving to the Army's ready reserve where he is now a major.

Lesser was reported out of town yesterday and could not be reached for comment directly. But Meyer said Lesser told him the signals creating the magnetic field "apparently came from across the street." Govignon has said he noted a man in a white shirt looking at him from a third-floor window of the old Congressional Hotel during the Wednesday afternoon inspection.

Crisp assistant Cathie Hogan said in an interview yesterday said that the window from which the man disappeared was on what she thought was the third floor of the building now used as a congressional office annex. A Capitol policemen in the lobby of that building said the offices in that vicinty were occupied by the House Administration Committe and the Republican Study Group.

Like the experts who were interviewed, however, Meyer pointed out that "that type of signal can come from a radio station, or certain kinds of machinery."

David Watters, a former communications expert for the CIA and currently a special consultant to the General Accounting Office, observed:

"The downtown Washington area is hot electromagnetically. AT&T has terminals all over the place. And a lot of electrical machinery will generate electro-magnetic radiation from what are called spark-gap discharges. The subway is also a possible source of electro-magnetic engery."

At the same time, the electro-magnetic field detected in Crisp's office -- and the speculation that it could have been caused by a microwave transmission -- is consistent with at least three surveillance techniques.

A microwave transmission could be used to power a "cavity resonator," a device made famous when the Soviets installed one years ago in a Great Seal of the United States in the U.S. Embassy in Moscow.

A cavity resonator -- which has no electrical connections itself -- would be installed in the room to be bugged and would be activiated by microwaves. Once activated, it would transmit voices from the room. But such a device was not reported to have been found in the sweep of Crisp's office and it is regarded, in any case, as a highly inefficient bug.

If a transmitter had been attached to the electrical cord, it could have been turned on and off by a microwave signal.

Microwaves and other radio waves, when transmitted into a room or a telephone system, have the ability to turn a seemingly innocuous device such as a transistor radio or the earpiece of a telephone into a transmitting bug.

Microwave transmissions are effective only when the transmitter and the receiving area are within sight of each other. Metal plates or buildings or human bodies can interfere with line-of-sight transmissions.

This could explain the phenomenon Govignon reported when he said the electromagnetic field at a point beside Crisp's desk was interrupted when a colleague stepped in front of the window.

"That's one area I would want to check again and again to confirm that interruption," said Allen D. Bell Jr., a retired Army counterintelligence expert who heads a firm that manufactures electronic counterintelligence equipment, including the Dektor, one of the devices used in last week's sweep.

Crisp has said she became concerned because she has been hearing "beeping sounds" on her home phone since April and her office phones in recent weeks. But experts said the noises could just be interference from a wide variety of sources.

"Usually a tap on a phone is silent unless it is of poor quality, installed by less than an amateur," said Barry Ashby of Ashby & Associates, which did the National Wiretap Commision report.

"Instead of all this sophisticated equipment we've been talking about," added Watters, "the most productive is a good, clean tap on the phone."