As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE "TOILET" WENT OFF AFTER TAKEOFF. FA SMELLED SOMETHING BURNING IN THE LAV AREA AND REPORTED A LIGHT HAZE IN THE CABIN. FLIGHT RETURNED TO MSP. COMPLETED MM409 NR 273156 REPLACEMENT OF LAV LIGHTING BALLAST AND LAV SMOKE DETECTOR. ALSO NOTED R PACK HAS STRONG OIL SMELL. REF LOG NR 1709548 FOR FERRY FLIGHT TO T/S R PACK.