Electrical problem

Could it be the ignition switch itself

It could.
Unplug it and if that is the problem the stuff will go off.
If they don't go off then it's in the wiring or a melted bulkhead connector.

Headlights, interior light, dash lights, tail and brake lights always have power to them.
Reverse lights usually don't light until the ignition is on and the same with signals.