I was looking for a way to make Christmas lights in vanilla Minecraft and found a fairly simple set of commands even a noob like me could execute. Unfortunately, they're heavily outdated. As I've said, I'm a pure amateur when it comes to commands, so I don't know how to convert it myself.
Essentially, its colored particles at the end of glass panes set to glow when a lever is flipped. It used floating invisible armor stands where the light was going to be and three command blocks, etc. etc.
I'll link the website I found the video and commands from. if there's a similar way or a conversion anyone could provide, I'll be eternally grateful.