The cheapest WiFi ON/OFF switch for controlling the lighting in your home

Hello

My question might be a bit silly, but let’s say I want to control the lighting in four rooms and also be able to view footage from wireless cameras that will be installed somewhere. The flat is already finished, so only wireless systems are really an option. So, to the point: Could anyone tell me at what price (obviously the lowest possible ) I could get a device with ON/OFF functionality and a WiFi interface? (ideally, it should fit inside an electrical junction box) The flat has WiFi and I assume there will be a lightweight computer running as a server – making everything accessible from outside.

I’m asking because I can’t be bothered to put together such a ‘box’ myself, and I can’t find anything sensible. There are some ON/OFF switches about, but they use Z-Wave technology, and besides, the cost per unit is 300 PLN!!

Thanks in advance for your reply
Best regards

Right, but on the website you mentioned, the flush-mounted switch costs 305 PLN, and it uses Z-Wave technology, which means you’d have to buy a controller for 260 PLN as well.
Thanks, but paying 1,500 PLN for 4 switches and a controller? To be honest, I’d rather rip out the plaster and lay the cables... At least ones that are interference-resistant
Is there really nothing cheaper?