When the freezer defrosts all of the water flows into a tray in the rear of the freezer, behind the sheetmetal, and then is supposed to drain down through a hose into the catch pan at the bottom of the fridge where it evaporates. What is happening is that the water does not completely drain before the freezer defrost cycle ends causing the water to freeze in the catch pan blocking the drain hole. When the freezer again defrosts, the water cannot drain and overflows down into the refridge. This may also be caused by dirt in the catch tray. My repair on two Amanas was to enlarge the drain hole allowing for faster draining. I had to rig a larger adapter to the drain hose to accomodate the larger opening.

The best way is to access the freezer coils which are generally behind the sheet metal in the rear of the freezer. That panel once removed will show the coils and the defrost heating elements, which by the way are working since the freezer is obviously defrosting. Locate the water catch tray below the coils and make sure both the tray and the drain hole are clean and clear of any dirt or pieces of insulation. Make sure also that the drain hose is clear all the way down and into the pan under the fridge. If you have found any reason for water obstruction, and have cleared it, reassemble the freezer panels and put the fridge back into use. Install the fridge with a slight tilt toward the rear, just enough that the door swings shut on its own, and with a slight tilt left or right toward the freezer water catch tray drain hole. This should be the end of it. If not the next step would be to enlarge the drain hole in the catch tray and adapt to the drain hose. Good luck.