I commented on exactly this on HN a few days ago - when I venture out these days, I notice some people wearing masks, and just in the short time I see them, pretty much every one has adjusted/fiddled with their mask.
The masks I've seen are of varying types, but I guess most are of the 3M DIY/building variety (that is, masks designed to be worn while doing building work).
...assuming the act of wearing the mask isn't the reason for touching the face in the first place (eg. adjusting the mask)