You're not the first to notice this (just Google John van Druten Bell, Book, and Candle and homosexuality). Van Druten was a (not very effectively) closeted homosexual, and his play--the source of the movie--ran on Broadway in 1950, at a time when Communists and homosexuals were the target of McCarthy and the HUAC, which was referred to even then as--what a coincidence!--a witch-hunt. So Van Druten writes a comedy about witches, and three years later, Arthur Miller writes a tragedy about the Salem witch hunt. Both enjoyed great commercial success. . .guess the McCarthyites didn't go to the Theahtuh--or wouldn't know a subtext if it bit them.