Instead of trying to put your appliance module outside, and risk it getting wet, why not add another outlet inside the house, near the existing outdoor outlet, or anywhere along the path of the existing wire that feeds that outlet. Re-route the wires that were going to the outdoor outlet to this new outlet instead. Then plug the appliance module into the new outlet, and plug into that a new wire leading to the existing outdoor outlet. If you are really lucky, there will be enough slack wire so that you can cut the wire going to the outlet and insert the new outlet in-between. In any case, you will need to put a plug on the wire feeding the outdoor outlet. Work safe, don't forget to turn off the breaker first! Good luck.