What was found
PRIOR TO LANDING, THE PILOT NOTICED SMOKE IN THE COCKPIT COMING FROM THE PILOT'S SWITCH PANEL. THE PILOT THEN TURNED THE MASTER OFF AND MADE A SAFE LANDING. INVESTIGATION FOUND THAT THE AIR COND TOGGLE SWITCH HAD FAILED AND BURNT. REPLACEMENT OF THE SWITCH ALLOWED THE SYSTEM TO OPERATE NORMALLY. NOTED THAT THE SWITCH USED IS A 20-AMP SWITCH WHICH IS PROTECTED BY A 20 AMP CIRCUIT BREAKER.