Is it possible to use the electrical conductivity of our body to start a small software?

Absolutely yes and to do so we will need MakeyMakey, a computer and Scratch 3.0 programming software.

In this tutorial you can learn how to program MakeyMakey with Scratch 3.0 to exploit the electrical conductivity of the human body and start a small software.

https://makeymakey.com/