Wilbur L. (Billy) Carnegie Jr., 36, a former employe of Seaboard Security Systems here, died Wednesday of coronary-pulmonary arrest at Howard University Hospital.

Mr. Carnegie had undergone brain surgery three years ago. Before that he had worked as a waiter in Oxford, Md., and in a PACTS (Parents, Administrators, Community, Teachers and Students) neighborhood workshop. PACTS was part of a plan proposed by former D.C. school superintendent Barbara A. Sizemore. It later was rejected by the D.C. school board. His most recent job had been as a "shopper" investigator for Seaboard Security.

He was born in Tucson, Ariz., and came here with his family as an infant. He graduated from Spingarn High School in 1961.

Mr. Carnegie had served as an altar boy at St. Luke's Episcopal Church for seven years and was awarded the medal of St. Vincent dePaul for his outstanding service. He also had been a Boy Scout leader.

His pen-and-ink drawings of presidents and celebrities drew responses of appreciation since Kennedy and from such performers as Sammy Davis Jr., Frank Sinatra and the Ramsey Lewis Trio.

Survivor include his mother, Ethel, of the home in Washington; his father, Wilbur L. Sr., a brother, Lawrence, and a sister, Barbara Slocum, all of Washington. CAPTION: Picture, WILBUR L. CARNEGIE JR.