As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - CREW REPORTED ELECTRICAL ODOR COMING FROM THE RIGHT AFT LAVATORY. EMERGENCY DECLARED RETURNED ORD LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. RE-INSTALLED RIGHT PACK DUCT BOOT THAT HAD SLIPPED OUT OF POSITION. SYSTEM GROUND CHECKED NORMAL OPERATION.