WHILE ON FINAL APPROACH FOR LANDING THE AMPHIBIAN AIRPLANE ON A MOUNTAIN LAKE, THE PILOT NOTED THAT THE RIGHT SIDE GEAR DOWN LIGHT FLICKERED. THE PILOT ABORTED THE LANDING AND DURING THE CLIMBING LEFT TURN OUT OF THE VALLEY, THE AIRPLANE COLLIDED WITH TREES. POST ACCIDENT INVESTIGATION DETERMINED THAT BOTH LANDING GEAR WHEELS WERE IN THE RETRACTED POSITION, AND THAT AN ELECTRICAL SHORT IN THE SYSTEM TO THE RIGHT SIDE FLOAT RESULTED IN THE FLICKERING LIGHT.