Kath...frost free refrigerators defrost themselves periodically and when they do, the water from the melting ice has to go somewhere. That somewhere is thru a drain tube to an evaporation pan. Often times the drin tube gets plugged up with a small chunk of ice or a glob of funk that grows in water. When this happens the water overflows and runs inside the fridge or on the floor... the best solution is to get to that drain tube and see if there is something stopping it up...as for getting to it, depends on make and model of fridge.