As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: FALSE LAVATORY SMOKE LIGHT ON OVERHEAD PANEL WITH ASSOCIATED AURAL TUNE AT FL390. FLIGHT ATTENDANT NOTED NO SIGN OF SMOKE OR ANY SMELL OF FUMES IN FIRST CLASS LAVATORY NOT ASSOCIATED WITH LAVATORY SMOKE LIGHT OR TONE. REPLACED FIRST CLASS LAVATORY SMOKE DETECTOR PER AMM 26-14-00.