What was found
EMERG LIGHT SWITCH: FOLLOWING FLIGHT, AFTER COMPLETION OF SHUTDOWN CHECKLIST, WITH EMER LIGHTS SWITCH OFF, EMER LIGHTS IN AFT OF AIRCRAFT AND OVERWING EMER LIGHTS REMAIN ILLUMINATED. REMOVED THE PINS AND REMOVED THE #8 SEAT FROM THE MOUNTING. ENSURED THE NR 3 EMERGENCY LIGHTING INERTIA SWITCH IS NOT STILL TRIPPED. REMOVED & REPLACED #3 EMERGENCY LTS BATTERY IA W 680A MM 33-50-06. SYSTEM OPS CHECKS GOOD IAW MM 33-50-00-710. VERIFIED PROPER INSTALLATION AND OPERATION OF#3 EMERGENCY LIGHT BATTERY PACK.