I'm using a pi pico W and a 433mhz transmitter to switch some lamps on and off.

Now I want a nice capacitive switch, which can also act to trigger the pi.
I'm hacking up a KingArt Smart Switch - because it provides an attractive, glass topped capacitive sensor. (It's not ESP based so it would be hard to reflash and use the onboard MCU)

The sensor pad on the PCB connects to the back of the glass front plate via this white foam pad - so I guess the foam pad is conductive/capacitive. It's also stuck to the PCM with what I guess is conductive/capacitive adhesive!