For almost three years, Executive Protection Service officer Dennis McCullough has worked midnight to 8 a.m., playing guardian angel in his blue and gold patrol car to slumbering diplomats and bureaucrats.

"I had the opportunity to work daytime during the pope's (visit)," McCullough says in a thick New York accent. "It was like 'Alice in Wonderland.' The stores were open. I couldn't fathom where all the people came from . . . It was great."

Each night after the television comedy "M*a*s*h," McCullough, 29, kisses his wife and three children goodbye and makes the 45-minute trip from Stafford, Va., into the city.

At 11 p.m., he is ready to join his partner in the patrol car.

"it gets very hard on your family," he says, the smile fading from his clean-shaven face. "It may mean giving up sleep or missing your one favorite TV show a week."

He is home again between 8 and 8:30 a.m. to have coffee with his wife and to see the oldest child off to school.

"It's hard on her keeping them quiet, keeping them amused," he says. "When I go to sleep, I die."

McCullough says he is uncertain when his night duty will end. But he hopes it is soon, stressing that his diet of 7-Eleven store microwave sandwiches is becoming increasing unappetizing.

Generally there's not even traffic. It's like living in a void," explains the former soldier and New York cab driver. "There's no variety to your life. It becomes repititous because your're so limited."

For McCullough, midnights mean dealing with the street crime usually handled by the Metropolitan police. While he does not complain, he says he would enjoy daytime work, "when the biggies are awake."

"This is not the kind of job you can just close up shop," he says. "It's a 24-hour job. Somebody's got to do it and right now its me."