They are just pool covers here is what John said in his video
":John: And these little covers here it says Suitable for wet location, These are just like a cover's for a swimming pool"
How it probably works is he has a sub panel or 4 breakers in the main panel that just control the arcade games and the light switches shut off power from the outlets here is another quote from john that further support this
"Up Here I have four twenty amp switches, ok and each on of these are wired to a Twenty-eight amp breaker we got Four Twenty amp breakers"
The Video
https://www.youtube.com/watch?v=GzjPFl7cVxI&t=10289sLight Switche talk start's at 2:11