What does Miss Strangeworth secretly do in The Possibility of Evil?

Miss Strangeworth has a dark secret. For the past year she has been writing anonymous letters to people in her town hinting that something bad may be happening in their lives which they are not aware of. She thinks that she is performing a public service and that, as the town's senior resident, it is her duty to issue these warnings. Instead, she is creating suspicion, anxiety, hostility, and other troubles.

On the day during...

Miss Strangeworth has a dark secret. For the past year she has been writing anonymous letters to people in her town hinting that something bad may be happening in their lives which they are not aware of. She thinks that she is performing a public service and that, as the town's senior resident, it is her duty to issue these warnings. Instead, she is creating suspicion, anxiety, hostility, and other troubles.

On the day during which the story takes place, she writes three of her poison-pen letters. Her letter to Mrs. Harper suggests that the woman's husband is having an affair with another woman and that everybody knows about it but his wife. Her letter to Mrs. Foster suggests that the old woman's nephew might have bribed her surgeon to cause her to die on the table when she has her forthcoming operation. And her letter to Don Crane suggests that his six-months old baby girl is mentally retarded. The short note reads:

DIDN'T YOU EVER SEE AN IDIOT CHILD BEFORE? SOME PEOPLE JUST SHOULDN'T HAVE CHILDREN SHOULD THEY?

Miss Strangeworth prints all these letters and their envelopes in big block capital letters so that she cannot be identified by her normal handwriting. Quite by accident, Don Crane finds out that the letter he received had been written by this apparently sweet little old lady. He takes revenge by chopping up all her prized rose bushes and sending her his own anonymous letter in which he writes:

LOOK OUT AT WHAT USED TO BE YOUR ROSES

This is probably an evil thing for him to do, and it seems to prove Miss Strangeworth's belief that there are innumerable possibilities of evil in the citizens of her town. The story is somewhat reminiscent of Nathaniel Hawthorne's "Young Goodman Brown," in which the protagonist finds out that all his apparently god-fearing neighbors are secretly devil-worshippers, including his own wife. In Shirley Jackson's better-known short story "The Lottery" it turns out that everybody in the town has a vicious streak and enjoys stoning one of their neighbors to death, as long as they have escaped drawing the black spot themselves. Miss Strangeworth is effective in putting people on their guards, because there really is a "possibility of evil" in everybody. It is obvious in "The Lottery" that everybody in the crowd is enjoying the thrill of stoning poor Tessie Hutchinson to death, especially Old Man Warner, who takes the lead saying, "Come on, come on, everyone." Sweet little old Miss Strangeworth thinks she is the only one in the whole town who is incapable of doing anything evil, and yet her greatest pleasure is in her evil hobby of writing poison-pen letters. The evil she senses in other people is really a projection of the evil inside herself.