Miner  --  Erma Ellen Milam, 74, formerly of Benton, died at 3:50 a.m. Aug. 15, 1993, at the Miner Nursing Center.   Born Oct. 8, 1918, in Mayfield, daughter of the late Coy Noole and Carrie Ellen Greene Mayfield, she was a retired machine operator for Thorngate Limited in Chaffee.  She was a member of the Morley Baptist Church.   On July 12, 1938, in Maynard, Ark., she married Leo Milam who survives of the home.  Other survivors include: one son, Gary Milam of Lewisville, Texas;  one daughter, Ruth Black of Millington, Tenn., and two brothers, Crulus Mayfield of Morley and Odell Mayfield of Sikeston; and five grandchildren, one great-grandchild.  One sister and one brother also preceded her in death.  Friends may call after 5 p.m. today at Amick-Burnett Funeral Chapel in Benton where services are scheduled for 10 a.m. Tuesday with the Rev. Jim Matthews officiating. Graveside services will be conducted at 3:30 p.m. Tuesday at Brockett Cemetery in Pocahontas, Ark.