As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT, AIRCRAFT DIVERTED TO PHX DUE TO CHEMICAL SMELL IN AFT CABIN AREA. AIRCRAFT LANDED AT PHX WITHOUT INCIDENT. INSPECTED AND FOUND MIRROR LIGHT C/B TRIPPED. AFT LAVATORY BALLAST HAD OVERHEATED AND WAS CAUSING SMELL. REPLACED BALLAST AND SOCKET PER BOEING M/M.