She guest starred on DYNASTY in 1982 and appeared in a few episodes of DAYS OF OUR LIVES as Kay Stanhope in 1976.
Singleton met Lucille Ball in the late 1940s during a performance of the radio show "My Favorite Husband"; a few years later, Ball invited Singleton to join the cast of I LOVE LUCY as Carolyn Appleby, Lucy's near-sighted neighbor and sometimes nemesis. She also appeared in several episodes of HERE'S LUCY and was in the 1980 TV movie Lucy Moves to NBC.