My idea is to create a light switch that is drawn on the wall, and when touched, it will turn on/off a switch controlled via ZWave protocol.
The idea comes from the Bare Conductive Touch Board https://www.kickstarter.com/projects/863853574/touch-board-interactivity-everywhere
Unfortunately, they do not have WiFi integrated, and the shields are pretty expensive.
So, the technical question is(
For simplicity, Bare Conductive Paint acts exactly as a wire, so we will call it a wire.): How can I make the Spark IO input know when I touch the wire with my finger? Do I need an extra cip or something? How can I do it as simple as possible?