As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THERE WAS AN ODOR OF SMOKE IN THE CARGO AREA AND IN THE AFT CABIN. THE SMOKE DETECTOR IN THE LAVATORY WENT OFF WHILE BOARDING PASSENGERS. INVESTIGATED AFT CABIN, FOUND LIGHT IN LAVATORY BALLAST BURNED OUT AND RELEASED SMOKE INTO AFT CABIN AND LAV. REPLACED BALLAST OF LAV LIGHT, OPS CHECK GOOD.