MABEL A. MILLER CASTRONOVA, 83, of Ringwood died Tuesday. Before retiring in 1977, she was a clerk for Brooklyn Union Gas Co., Brooklyn, where she worked for 30 years. She was a member of the Ringwood Presbyterian Church. There are no immediate survivors. Her husband, Joseph T., died in 1965. Services will be Thursday at noon at Richards Funeral Home, Riverdale, with entombment at Fairview Mausoleum. Visiting will be Thursday from 10 a.m. to noon.