What was found
UPON ENTERING THE DOWNWIND FOR LANDING THE GREEN LIGHTS INDICATING GEAR DOWN WERE DARK. THE PILOT RECYCLED THE GEAR SEVERAL TIMES BUT THE RESULTS WERE THE SAME. LIGHTS WERE OFF, GEAR HANDLE RETURNED TO NEUTRAL, AND NOSE GEAR APPEARED DOWN IN THE MIRROR. I MADE A LOW APPROACH AND TOWER SAID THEY APPEARED DOWN. PILOT DECIDED TO RETURN TO DEPARTURE AIRPORT AND NOTIFIED THE TOWER THERE OF THE UNSAFE GEAR AND MADE A NORMAL LANDING. MECHANICS VERIFIED THE GEAR WERE LOCKED DOWN AND THE PLANE WAS THEN TOWED TO THE HANGAR. THE PROBLEM WAS DETERMINED TO BE IN THE PANEL LIGHT DIMMER SWITCH (PN A-10294-1) THROUGH WHICH THE CIRCUIT FOR THE GEAR LIGHTS RUNS. THE SWITCH HAS BEEN REPLACED AND ALL FUNCTIONS ARE NORMAL.