Summary

Basic fischertechnik stone for TTP223 Touch Switch Sensor. My color code is red for ‘normal’ touch behaviour, and black for the modules with solder-jumper ‘B’ closed (T-flipflop On/Off behaviour)

I've made two models. One has the PCB in view and one slim model (5mm thick) inspired by juh. I printed the latter with transparent filament, so that the stone is a kind of diffuser for the LED at the bottom of the sensor.