What was found
AFTER LANDING IN ACK, CREW SHUT OFF ALL EXTERNAL LIGHTS EXCEPT BELLY STROBE AND NAV LIGHTS. NOTICED SMOKE COMING FROM NAV LIGHT SWITCH/BREAKER. SHUT OFF SWITCH, TAXIED TO GATE, AND NOTIFIED MAINTENANCE. FOUND RT WING NAV LIGHT POWER WIRE SHORTED TO GROUND, CIRCUIT BREAKER SWITCH INOPERATIVE, DID NOT TRIP. REMOVED AND REPLACED CIRCUIT BREAKER SWITCH. CHECKED OK AFTER REPAIRING WIRING.