As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DCA - WHEN PLACING THE EMERGENCY EXIT LIGHT SWITCH TO ARM WITH THE AIRCRAFT POWERED, THE AFT EXIT AND AFT PORTION OF THE EMERGENCY EXIT LIGHTS COME ON. MAINTENANCE REPLACED THE AFT EMERGENCY POWER SUPPLY UNIT AND BATTERY. OPERATIONALLY CHECKS OK.