Board Schematic for wireless switch?

I am not much of an electrics guy and don’t really know most of those things, but I want to make something like a Sonoff Basic, something that will splice into my actual wire and be able to control it wirelessly. Also I want to make some kind of wireles plug. I’m doing this because it’s cheaper(even the cheapest one will be expensive with shipping to my country) and most things don’t ship here.
I’d be grateful if someone gives me schematics or a tutorial to make a board or device like the sonoff basic and also on making a plug to use with openhab. I looked for tutorials but couldn’t find any so far except for the plugs

thank you

Unfortunately, this is an openHAB forum. While there may be people here who can help you will find much better luck looking at a DIY electronics, ESP8266, Arduino, Raspberry Pi, or some other such forum. Most of us can help interface it with OH but not the electronics part.

I forgot to add one thing, I’m trying to make a board that can be activated wirelessly but also used by the switch as my parents would rather use the switches. I’ve seen someone who made this and posted a video of it on youtube but I think he only gave the firmware/codes and no board schematics etc.

Would be greatly appreciated if someone helps me out