As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THERE WAS A BURNING SMELL NEAR UPPER DECK ROW 12. OVERHEAD CEILING LIGHT SOCKET MELTED AND SPARKED FORWARD AND AFT OF ROW 12. BOTH FLORESCENT LIGHT BALLASTS WERE DISCONNECTED. SUPPLEMENTAL DATA UPDATE FOUND BROKEN GROUND CONNECTION ON LIGHT ASSEMBLY. REPAIRED GROUND CONNECTION. REPLACED SOCKET AND BALLAST.