The special committee investigating the Ehrlich administration's personnel practices voted yesterday after a closed-door session to subpoena its first two witnesses to testify at a Dec. 13 meeting. Though the committee and its attorney declined to identify the state workers, opting instead to refer to them as witnesses "A" and "B," George "Skip" Casey, a former director of human resources at the Maryland Department of Transportation who was fired last fall, is expected to be one of them. --Snip-- Casey, who is the assistant vice president for human resources at Loyola College in Baltimore, wrote a six-page letter to legislative...