Electrical line repairers, radio dispatchers and meter readers in Southern Maryland are joining forces with police in four counties and with state police this week in a new crime prevention program designed to cut back on daytime residential burglaries and assaults.

The workers are employed by Southern Maryland Electric Cooperative Inc., which services 69,000 residences and is the only source of electricity for southern Prince George's County and St. Mary's, Calvert and Charles counties, where the crime watch program is being undertaken.

If the electrical workers see anything they think needs attention they are instructed to use their CB radios or telephones to call the nearest police station, said Sgt. Casey McDevitt, spokesman for the Charles County Sheriff's Department.

"We're not asking anyone to go out and spy on anyone, but they're out there reading meters and working on electrical lines and they can help cut the opportunity for crime," he said. "Hopefully, would-be thiefs will stop and think 'somebody's watching me.' "

Walter H. Smith, general manager of the electric cooperative, whose 330 employes were trained this month in crime detection and prevention, said: "Crime is on the upswing in rural areas. People don't lock up. . . . We see it every day. There's an awful lot of breaking and enterings, rapes, assaults, property damage."

"Our employes are out in the community with their radio equipment anyway, and we saw this as a way of putting our eyes and ears to work for the police," Smith said.

Smith said his company owns 100 radio-equipped cars and trucks. All the drivers will participate in the program as they make customer calls in a four-county area.

Employes have been instructed to be on the alert for for strange cars, open back windows of homes where residents are known to be away, "the person conducting business out of a paper bag or the suspicious door-to-door salesman . . . your basic crime-prevention stuff," McDevitt said.

McDevitt said police do not see any danger in the citizen force becoming a roving vigilante group.

"These are responsible citizens. They want to help and they have specific instructions not to take the law into their own hands. They are merely to report suspicious activity and we will check it out," he said.

Since 1981, commercial and residential burglaries have jumped along with the region's population, McDevitt said.

In 1981, there were 437 reported burglaries in Charles County. Through Nov. 20 of this year, 466 burglaries were reported to police, McDevitt said. Burglaries peaked in 1982, when 578 came to police attention. Last year, 505 commercial and residential break-ins were reported, he said.

Armed robberies are "not common -- about 30 a year in Charles -- and we want to keep it that way," McDevitt said. "That's another reason we are asking for citizens' help."

McDevitt said he will approach all of the region's large employers, whether or not they have fleets of radio-dispatched vehicles, to see if any are interested in training their employes.

Participants in the crime watch program must be willing to testify should they be needed as witnesses in specific criminal prosecutions a major departure from other crime prevention programs, McDevitt said.

In other area crime detection programs, such as Crime Solvers and TIPS (Turn In a Pusher), police rely on anonymous tipsters for clues about investigations and often offer rewards to those whose information leads to an arrest and indictment.

"No rewards are offered and we guarantee no one's anonymity. That's a key component of this program," McDevitt said.

Similar programs involving employes of electrical utility companies are operating in Pennsylvania and Texas, Smith said. And McDevitt said Baltimore City taxi drivers also report suspected crime to local police using their radio dispatchers.