Transition to electronic parts
In practice we leave the toggle switches actuated by human fingers and will use miniaturized switches driven by electricity. An electromagnetically actuated relay switch may be our intermediate server as it had been in computer history with Zuse and Aiken more than half a century ago.
Today transistors are used.
But I cut out the explanation of a transistor switch. I only present its possibility to conduct from C to E if there is a tiny opening current from B to E.
move on