I've read that you can find lines by making a cornstarch/vodka mixture into a thin paste. brush it liberally onto the area where you are planning to drill and run the fridge on max for a while. The idea is that the mixture will dry faster in the areas where the lines run, where they get hot. This might not work well if the inside of your fridge is white, I would imagine.
What about liquid nails or construction adhesive?