Maigret's Madwoman (Inspector Maigret #72) by Georges Simenon, Siân Reynolds (Translator); 1970/2020. Softcover.

A kind but seemingly paranoid old lady turns to Inspector Maigret for help, believing someone has been in her apartment. Things have been moved around, she says, and she can feel the presence of the uknown intruder. Against the judgment of his subordinates, who insist the woman is imagning things, Maigret decides to pay a visit to her Parisian apartment to investigate--but is he already too late?