As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH, EMERGENCY EXIT LIGHTS AND EMERGENCY LIGHTS IN CEILING CAME ON WHEN LANDING GEAR WAS PUT DOWN. ALSO CAME ON ONCE DURING TAXI . BOTH TIMES WERE ONLY ON FOR ABOUT 1 SECOND. SUSPECT APCDU IS FAULTING. R & R THE APCDU & GENERATOR RELAY IAW AMM 24-21. NO FAULTS NOTED THIS TIME.