What was found
PILOT REPORTED 3 RED LIGHTS (DOOR LIGHTS) AFTER DEPARTURE FROM YIP AND RETURNED TO YIP. MAINTENANCE JACKED AND SWUNG GEAR OPS CK GOOD. AIRCRAFT DEPARTED YIP WITH SAME PROBLEM AND RETURNED. AIRCRAFT JACKED AND GEAR SWING PERFORMED POSITION OF ALL SWITCHES CK GOOD, OPS CK GOOD. AIRCRAFT DEPARTED YIP WITH SAME PROBLEM AND RETURNED. MAINTENANCE ADJUSTED LANDING GEAR SWITCH AND PERFORMED GEAR SWING, OPS CK GOOD AIRCRAFT HAS NOT HAD PROBLEM SINCE ADJUSTMENT.