if it's a top freezer model, depending how old it is, there is a sort of cup in the very top of the back of the refrigerator section. it is hidden sometimes underneath some plastic parts on the top of the refrig. if you have a plastic tube running down the back of the outside of the unit, this little cup is probably your problem. run it under some hot water and, tada, no more leak.

this is only applicable on older models...

hope this helps...

roy