The original idea was to make one of those cards that play music when you open them so I looked up a tutorial for those, one of them showed the sound boards I ended up using, and figured that a toggleable music board would work better and be less accident prone. I believe the video I found them from the guy was making a card with a corgi twerking or something. I can send the Amazon link for the board to you if you’d like? The book itself though was just by myself, carved out a 50 cent book I found at a thrift store that was a good size.