Whirlpool Genuine OEM WPW10239390 Refrigerator Defrost Timer.
This part works with the following brands: Whirlpool, Maytag, Admiral, Kenmore, KitchenAid, Magic Chef, Roper, Modern Maid, Estate, Caloric, Crosley, Inglis, Hardwick, Jenn-Air, Sears, Amana, & Norge.
Possible Repair Solution For:

Frost build up, refrigerator is too warm, refrigerator is too cold, freezer is too warm, freezer is too cold, runs for too long.
Please Note: This is intended as a guideline only, as other items can cause the same symptoms.