I built a working version of the Christmas lights from Stranger Things (that Joyce used to talk to Will in the upside down) for a friend's Halloween party. It used an arduino board, a string of addressable LEDs, and a little web interface that guests could use to send messages to the lights.

It was so much fun to build and a hit at the party. I wish I had the opportunity to build more things like it :)

https://github.com/zbtaylor/stranger-things-lights