Asking for advice on remote control of playhouse lights

I built a playhouse in back yard about 80 feet from back porch, its attached to a small shed with electric installed. I didn't add electric to playhouse because of safety reasons. Kids are reluctant to use after dark. I've tried those battery powered lights you stick on the wall for lighting. Didn't particularly work out well. The other day the wife picked up a system were you still use the battery light LEDs, but the switch is battery operated with an on/off switch, transmit up to 20 feet. Well as you can guess that didn't work so well. Got me to thinking. Kids are a little older now and I want them to sleep out over night so I need to improve the lighting system in playhouse. I could install a metal protected covered light in the down stairs and upstairs of playhouse and make it pretty safe now. What my question is how could I wire the playhouse with two lights and use a remote control to turn lights on/off from the house? Thanks