If you have any spare connectors, particularly if you have a bag you do not like, use them and put some silicone sealant to fill the end where the cable would go. (I know I have bag that I regret buying as they are awful) This will protect the unused connectors. Also, if you cover the connector part of the switch and paint the switch with a clear plastic paint it will seal and protect the switch against the rain. I would still put the switch in something to protect it from the weather. Even an old peanut butter jar will give it some protection. Cut a hole in the lid and tape it upside down to a post. It can breathe out the hole in the bottom and keep the rain off the switch. If you want it to look good, a proper enclosure is the way to go. If cables are making a u bend to go into the enclosure, a cable tie or something at the bottom of the U will help keep the water from running back up the cable into the enclosure. Yes water can run uphill, at least for a short distance.