What was found
THE FLIGHT CREW REPORTED THAT DURING POST FLIGHT CHECKS WITH THE EMER LIGHTS IN ARM POSITION, THE RIGHTHAND CABIN LIGHT OVER SEAT 6 AND RIGHT FORWARD EXTERIOR EMER LIGHT, EMER LIGHT IN RIGHT LANDING LIGHT AREA LIGHTS WERE NOT ILLUMINATING. THE MAINTENANCE PROVIDER TROUBLESHOOT PERFORMED AND FOUND INERTIA SWITCH OF BATTERY PACK NO4 DOESN'T WORK PROPERLY. THEY REPLACED THE INERTIA SWITCH WITH A NEW TEXTRON SWITCH. OPS CHECKS WERE SATISFACTORY, AND THE AIRCRAFT WAS RETURNED TO SERVICE.