Product review (2 stars): Lesson learned: use the original manufacturer's part when possible, even if it costs $10 or $15 more
My experience with this repair is that when replacing Whirlpool Refrigerator Cold Control Thermostats, is is best to replace the thermostat with one made by Whirlpool and not by some third party.  I bought this thermostat for a friend's refrigerator, but after running the refrigerator for a couple of days, everything in it began to freeze, even though the setting was set to normal.  It apparently either needed recalibration, or was defective.  I returned it to Amazon.com and bought the one made by Whirlpool.  It worked like a charm.

Lesson learned: use the original manufacturer's part when possible, even if it costs $10 or $15 more.