Needed a Sonoff Basic enclosure with more space in it that others I've seen on this site. This enclosure houses the Sonoff board, it does not hold the board in its original case.

My design gives an ample amount of room to route a ground wire from a 3 wire cable like an extension cord or power strip and is tall enough to fit a switch into the lid without it contacting the board inside. Also has enough room at either end to deal with stubborn, thick wires that need room to bend.

Included two different versions of each the box and the lid.

One box design has a 9.5 mm diameter hole on each end that has fit well with most round cable power strips I've used it with. The other box design has a 7.5 x 4.5 mm square hole at each end that works well with two wire cable like found on some lighter duty extension cords and appliances.

One lid is simply a solid lid, the other has a 17 mm hole offset on the lid that will align with a space in the box that don't interfere with the Sonoff board inside.

You can mix and match box and lid designs, they fit universally.

Used 1" construction screws to secure the lids. Screw holed are countersunk. The fit is pretty snug but lid may fall off if not secured.

Also made some wall brackets to mount it on a wall.

Once wired up, I used small zip ties on the cable still sheathed portion of cable inside of the box to take strain off of the Sonoff terminal connections.

Included .obj and Fusion360 files.