My GE Outdoor ZWave SmartSwitch recently ceased working and I had some sonoff basics lying around so started out to build a weatherproof case to use under my deck and control the lights around the pool.  

I originally planned to use an O-Ring design but abandoned that with a snap on lid design w/ channels. It has two holes for using PG7 or with some modification PG9 grommets you can purchase or find on McMasterCarr and print yourself.   I did combine it w/ some left over jumper wires from Lutron switches and some snap fit connectors.