Got up this morning to find the freezer defrosted and water in the floor. The refrigerator is still cold. Is the most likely problem the defrost timer? If so, where is it located. I looked through a WP parts manual but could not find a defrost timer listed. Any help would be appreciated!

Some new ones don't have one, but if it does it may be beside the thermostat or kind of under it, or under the refrigerator. Look at these: https://dl.dropboxusercontent.com/u/8010163/Whirlpool%20Refrigerators.zip You also need to check the heater and the terminator.