As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CBN FILLED WITH SMOKE UPON LANDING AFTER F/A TURNED ON OVHD LIGHTS. FOUND GROUND STUDS FOR APU START BAT TO SHOW HEAT DAMAGE. CLEANED AREA AND SECURED STUDS AND RECONNECTED WIRING. DEACT APU, ATL TO ROUTE A/C FOR EO 6-66173 APU GROUND STUD WIRING MOD.