Anyone over the age of 50 probably can remember bedroom nightstand clocks that glowed soft green thorough the night, a convenient way for insomniacs to check the time, but deadly for the factory workers who assembled those marvels of modernity. Avonworth High School's fall play, "Radium Girls," which runs Nov. 18-21 at 7:30 p.m., with a Saturday matinee at 2 p.m., dramatizes the plight of women who painted the dials with radium, a miracle cure discovered by Madame Curie and used for the shrinking of tumors.