As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED SMOKE CAUTION MSG IN FLIGHT WHILE PAX WAS IN LAVATORY. INSPECTED LAVATORY & FOUND NO EVIDENCE OF SMOKE IN LAVATORY. AFTER THOROUGH INSPECTION OF SINK & TOILET ELECTRICAL COMPONENTS. GAINED ACCESS TO LAVATORY SMOKE DETECTOR & FOUND CONNECTOR DISCONNECTED TO SMOKE DETECTOR. RECONNECTED CONNECTOR & OPERATIONS CHECKED IAW AMM 26-13-01. OPERATIONS CHECKED GOOD.