Just thinking more about this (for my 00 line that I am putting servos on maybe) so I can hip hop 2 power wires to each sevo and only need 1 further wire to each point for the signal? Which is the control wire.It is (normally) especially if everything is local..
However, it is possible to run a single 'control' wire, to more remote locations, with a locally derived power supply. - For example, something derived from a solar garden light.
PhilP