I’m looking for physical dummy switch recommandations. More precisely, I want switch that I can wire in the wall but that only record if the physical switch has been trigger NO relay inside of it. I just want it to be able to trigger something in home assistant without being directly wired to the appliance.
So just a wall power switch that record if the physical switch has been trigger. Something like the sonoff mini but without the relay.
Thanks in advance for your help 
There are plenty of scene switches. If you need something mains powered, Aqara switch with neutral can send action to HA and it don’t need load to be attached.
Just use any switch and don’t connect the load surely.
I use multi channel Zigbee switches like these behind wall plate switches:
Like @Arh says, you don’t have to connect up any lights etc. however if you connect S1-S4 to the wall plate switches then the state of these will toggle in Home Assistant.
Great thank you !
But I have a single switch that controls a light and I wanted to add another one without needing to rewire my home. So the idea is to put a module behind the original switch and another one behind the new switch. And I would like to be able to bind them with ZigBee in order to not be dependent on home assistant, do you have any suggestions of module because I struggling to find module that support binding in zigbee2mqtt
Have a look at the Ikea Zigbee switches, I believe that these can be binded directly but have not tried this myself. They sell a smart bulb with a wireless switch as a pack and I think these can be connected independently without the need for a hub.