RV GAS/ELECTRIC REFRIGERATOR BEGAN LEAKING COOLANT GAS (AMMONIA) INTO COACH MAKING OCCUPANTS VERY ILL AND LIGHT HEADED. GAS SEEMED TO ALMOST IGNITE BEFORE AREA WAS OPENED TO THE ACCESS PANEL OF COOLING UNIT AND VENTED. COOLANT GAS WAS OPEN TO LP GAS HEATING ELEMENT FLAME FOR POSSIBLE UNCONTROLLED IGNITION LEADING TO POSSIBLE FIRE TO COACH. AREA EXTREMELY HOT WHICH SUSPECTS A SMALL FIRE OCCURRED. REFRIGERATOR COOLING UNIT HAD TO BE COMPLETELY REPLACED. *TR