As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT ATTENDANT REPORTS ALL CABIN LIGHTS INCLUDING EMERGENCY LIGHTS INTERMITTENTLY COME ON FULL BRIGHT UNCOMANDED. 4 TIMES ON 3 HOUR FLIGHT. REMOVED AND REPLACED CABIN INTERCOMMUNICATION DATA SYSTEM NUMBER 1 PER AMM 23-73-34.