No ... that is not the system on Focus.
I used to look after all the Focus wiring among others for FMC.
Lighting switch problem .. or a main fuseboard problem ... BUT there may be a short into the lighting circuit in some area .. like rear lamps .. anywhere there is lighting AND lives. You'd better check carefully around first. The main fuseboard is a plug-in item (multi-plugs and colour-coded)
Never heard of this problem from any European dealer I used to support.