As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED. EMERGENCY EXIT LIGHTS ILLUMINATED IN THE BUSINESS CLASS AFT SEATS DURING APU START. REMOVED AND REPLACED WIRELESS EMERGENCY LIGHTING SYSTEM CONTROL UNIT AT WCU01 (AALA20170320003) AND WELS BATTERY AT WCU23 IAW AMM 33-5-07. OPERATIONAL CHECK GOOD.