For a simple multi light (2-4) setup would have all the lights and switch in the same class. The drag the actor in, move each light to its position and move the switch. When the switch is toggled it can talk directly to all the lights.
For more lights use an event dispatcher in the Switch class. Then create a class for the light. Next have you Light BP’s simply create a bind to the switches dispatcher event(s). This approach can be used for 1-1000+ lights on a single switch.