I found a "Dr. Mad Thrust electronic on/off switch" and it requires no external/separate power. And has the JR plugs on both sides as needed. I will plug it into the 5th port on the receiver and hope my transmitters channel 5 switch works as I plan.🤞😁

You can buy these on Ali Express for about $4 US. You can take power from your ESC BEC output before it goes to your receiver (much safer to use a separate battery so as not to overload your BEC) - depends on the voltage / Watts requirement of your lights but these will take from 0-40v and are switched by your REC (ie voltage in and out and plug to REC)- see pic
They will even work on rotary switches once voltage from REC gets past a certain % (about half rotation). They work really well.

....or make your own....

https://www.lutonmodelboat.co.uk/hints/RC%20Switch%20Iss3.pdf

Hobbyking sell a RC operated switch which will run either from a seperate battery or through the BEC. I think it is a Turnigy item and cost around £6. The only wiring difference is that if used on a second battrery, the negative wire has to be connected in parallel to the main BEC supply battery to work.

Hi, Rx switches,

Reference Rx switch post.

I think I can help, I make a switch that is operated by the radio controls, it uses one channel to operate two independent switches. If you like, log in face book marketplace and you can see this switch there.