What was found
SDF - FLT 1732 - DURING CLIMB-OUT, THE FORWARD CARGO DOOR WARNING LIGHT ILLUMINATED. CAPTAIN DECIDED TO RETURN TO FIELD AT SDF TO VERIFY SECURITY OF THE CARGO DOOR. FLIGHT LANDED WITHOUT INCIDENT. NO EMERGENCY WAS DECLARED. CAPTAIN NOTED THAT ON LANDING, THE CARGO LIGHT EXTINGUISHED. MAINTENANCE CHECKED THE FORWARD CARGO DOOR SWITCH, MOUNTING AND WIRING. ADJUSTED PLUNGER ONE TURN. OPERATED DOOR SEVERAL TIMES. OPERATIONAL CHECK OF DOOR WARNING SYSTEM GOOD. (X)