What was found
FLIGHT 8678/ENROUTE PDX - MFR, AIR TURNBACK DISCREPANCY: AFTER TAKEOFF, THE PILOT REPORTED AN ELECTRICAL BURNING SMELL AND SMOKE IN THE COCKPIT. AIRCRAFT WAS RETURNED TO PDX. NO EMERGENCY WAS DECLARED AND THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. FIRE PERSONNEL WERE DISPATCHED TO THE AIRCRAFT UPON LANDING. CORRECTIVE ACTION: MAINTENANCE DISCOVERED A MELTED TERMINAL ON THE RH LANDING LIGHT SWITCH. REPLACED THE LANDING LIGHT SWITCH AND LANDING LIGHT CIRCUIT BREAKER. OPS CHECKS GOOD.