Window Shopping (standing there with doors OPEN) allows all the COLD air to escape and WARM air to enter.
Then fridge has to cool that warm air down....moisture in that warm air condenses
Warm air can also come in via the drip pan drain line if the end of it is not in the recovery cup in backside of fridge compartment which has some water in it.
Check the door seals........dollar bill pulls out of closed door easily seals are NOT stopping cold air out/warm air in (Try several areas around the doors)
The higher the humidity the more moist air can enter fridge everytime doors are opened