Turn battery operated lights on/off, is there a solution available?

Christmas is here, lights goes up all over the house, including some battery operated decorative lights.

Is there a battery operated switch that doesnt require any power leads that can replace the switch in the fixture?

I’m comfortable with soldering a few leads in place, but lack the skills to actually make something from scratch.

I have RF433 and Z-wave controllers.

Same question. Could you get something working?