In Shirley Jackson's short story "The Possibility of Evil," Miss Strangeworth is an elderly lady of the town who feels a moral obligation to warn other people of the potential evils that may befall them in life. She writes anonymous letters to people in order to "open their eyes" to "possible evil lurking nearby." The paragraph of the story that explains her motive for writing the letters also says that Miss Strangeworth "never concerned herself with facts" in the letters since she felt it was important to raise people's level of suspicion. We are told that Miss Strangeworth's opinion on the matter is that "as long as evil existed unchecked in the world, it was Miss Strangeworth's duty to keep her town alert to it."
Some of the "evils" that she has forced people to consider are of the more mundane sort, such as adultery and the birth of a child with retardation. Other imagined evils are more elaborate, such as the idea that someone's nephew might bribe a surgeon to fatally botch that person's upcoming surgery in order for the nephew to maybe receive his inheritance sooner. She has been ruining people's relationships and sense of security for an entire year with this letter-writing hobby. Unfortunately for Miss Strangeworth, the vigilance that she has been trying to teach to her neighbors is ultimately turned against her. When one letter recipient discovers that she is the author of the rude letters that have been received all over town, Miss Strangeworth's beloved rose garden is vengefully destroyed.