Apparently a lot because he got upset yesterday that I said something else is missing.
And I did look for a full month before bringing it to his attention because it was something more expensive and I didn’t want to be falsely accusing him.
Grounding and taking electronics doesn’t seem to be touching the problem so I told him every time I know something is missing I will look diligently. If I don’t find it, he will have 1 day to return it. If not, I donate one of his Christmas presents to someone in need. I have no clue what else to do. Nothing is working.