Hmm, my first guess would have been that you have been a target of "brushing" [1].
In a Reddit thread from 2020 [2], multiple people mention that they received surgical masks they did not order.
[1] https://www.bbb.org/article/news-releases/20509-amazon-brush... [2] https://www.reddit.com/r/tulsa/comments/hpe8s1/just_got_a_su...