Binary input / modular buttons / keypads

Hi

Not sure even how these are called, may be the reason I can not find anything appropriate …
What I’m trying to make/buy is input device which could be installed in box with few standard ON/OFF switches or plain buttons.
I found Osram Lightify device which is exactly what i need:
https://www.osram.com/cb/lightify/lightify-pro/lightify-pro-product-pages/lightify_pro_pbc.jsp

Expect I would like it to be regular ethernet more appropriate for new installations. I would like to avoid Zigbee and other wireless stuff.
It should also be cheaper, this PBC is 100+ euro/usd per 4 switches.

Could you suggest some build/link for device which is made for this specific use ?
It should be small enought to go into box, and above it should be space for regular modular switches which are very popular in Europe, 10+ companies make similar stuff in various colors/sizes/etc which will make it very customisable and good looking.

Here is an example of regular modular switches/buttons:

Thanks