Final answer:
Miss Strangeworth's letters are meant to act as warnings to her neighbors about potential issues she suspects, with the belief she is preserving the town's perfection. She leans on suspicion over fact in her writings.
Step-by-step explanation:
The purpose of Miss Strangeworth's letters in "The Possibility of Evil" by Shirley Jackson was to maintain her self-assumed role as the town's moral guardian. She believed it was her duty to alert her neighbors to potential issues within their lives, doing so anonymously to avoid direct confrontation. These letters are based on her suspicions rather than fact, with Miss Strangeworth feeling justified in her actions, convinced she is helping preserve her town's quaint perfection. Miss Strangeworth's letters stem from her views and judgments, not concrete evidence, and she operates under the belief that her involvement, however meddlesome, is ultimately for the greater good.