This is a case for the SONOFF 5V/12V Inching/Self-Locking WiFi Switch Module such as this one oLikewisen Amazon. It features cutouts to access the wire terminals, a hole for the Micro-USB power, as well as buttons and light pipes for the LEDs.
The lid is provided with both break-away supports in the countersunk screw holes, and without. I had no issues breaking them out but your printer may vary. Likewise, I have included the buttons with a brim and without. The one with the brim is intended to be printed with the bottom layer in concentric rings to allow tear-off.
The author hasn't provided the model origin yet.