Letters to Santa is a common thing for young children to do.
What I remember about writing a letter to Santa is posting it and wanting to see the Address on the envelope. I believe I knew Santa wasn’t real, I felt like all the kids in my class knew by the age of 6, but I went along with it because well it was fun and also for the presents.
I very much wanted to know where that letter was going because I felt like I would have the proof that grown ups were very much lying to us and stringing us along and making us write these letters to keep us quiet.
I am not sure if it had my address or a relatives/friends or even just a made up one to be honest.
I found out that Royal Mail actually have a designated address to send letters to Santa and that they actually write back to as many people as possible if they provide their name and address. That is pretty cool.