One example that just screams at me is the misuse of N95 masks. The public is wearing them with the belief that it protects the wearer from the general public, when the direct opposite is the truth -- N95 masks protects the general public from the wearer. These masks are good for particulate matter like smoke; not microbial airborne virus' which requires dual carbon filters, for example:
View attachment 86337 OR View attachment 86338
N95 respirators can be safely decontaminated without undermining functional integrity only two or three times, a government study showed.