Answer:
One false belief people had was that three planets caused the plague by creating a conjunction. Some believed that flowers, herbs, and perfumes would get rid of the bad air or “miasma”, a belief that if you smelled it you to would become horribly sick.
Another belief that caused the plague was that the cats of that time were the servants of Satan and that they were to be wiped out. This caused the plague because when the ship rats came off the ships nothing killed them causing their population to rise along with the disease.
A pope believed that if he placed himself within a burning circle he would be protected from the miasma, and he was but it was because the fleas that came with the rats could not reach him. It was rare to bathe at all back then (Church's deemed it unholy to) so their immune systems were already down so when the plague hit it was devastating killing over half of the populace in Europe
I hope this helps you!!!