What was found
LANDING GEAR RETRACTED, GEAR MOTOR SHUT OFF, BUT HAD NO UP AND LOCKED INDICATION. AIRCRAFT RETURNED AFTER AN UNEVENTFUL LANDING. INVESTIGATION REVEALED LT UPLOCK MICROSWITCH HOUSING BROKEN IN HALF. SUSPECT CAUSE, MICROSWITCH HOUSING MADE OF PLASTIC, CRACKED AND BROKEN IN HALF DUE TO TIME IN SERVICE OF SWITCH - 16 YEARS.