you could record a short video of your supervisor every time you see them without their mask. If the higher up person wants to send you home, show him the videos and say the supervisor has to be sent home as well. if they have a policy and want to enforce it, they can't selectively enforce it - all or none. I bet you wont be sent home then. but they will probably just try to find something else to nit pick about till they can get you fired.
you could record a short video of your supervisor every time you see them without their mask. If the higher up person wants to send you home, show him the videos and say the supervisor has to be sent home as well. if they have a policy and want to enforce it, they can't selectively enforce it - all or none. I bet you wont be sent home then. but they will probably just try to find something else to nit pick about till they can get you fired.