DIY Traffic Light For Kid's Bedroom

My cousin turned 8 years old and for his birthday he wanted something that could prevent his mom or anyone from entering his room without permission. Specifically, he wanted a stoplight. Naturally this appealed to my diy brain and I started working on it. I had no plan, I just wanted to make a wooden box with a red and green light, a batteryholder and a switch. Unfortunately I didn't have the right switch available so I had to mount separate switches for the red and green light. My cousin didn't bother with such technical details :)