Question: We are hiring a carer to look after our mother. As she is not Jewish, do we need to place a mezuza on her door?
Answer: The Rema (YD 286:1) writes that one who shares a house with a non-Jewish roommate is not obligated to affix a mezuza to their door. The Gemara (Yoma 11a) teaches that the city gates of Mechuza did not have mezuzos. As the non-Jewish inhabitants may have suspected the Jewish residents of witchcraft, it was deemed dangerous. The Bach (YD 286) and Taz (YD 286:2) explain that this is why modern city gates don’t have mezuzos. Additionally, we are concerned that the mezuza may get mistreated (See Shach YD 286:6).
The Shulchan Aruch (YD 291:2) writes that the obligation to affix a mezuza is on the one living in a home rather than the owner. Therefore, one renting a house to a non-Jewish person should not affix mezuzos on that house.
The Aruch Hashulchan (YD 286:3) writes that one who employs a non-Jewish person who lives in their house is obligated to affix a mezuza on their bedroom. He explains that this is not the same as one who rents their room out to a non-Jewish person, as when they are employed and living in their house, that room is considered to be one that the Jewish homeowner is using for their employee (See Teshuvos Vehanhagos 1:650).
R’ Shraga Feivish Schneebalg (Shraga Hameir 4:20:2) writes that if one has non-Jewish people working in one’s office, one does not need to affix mezuzos in their offices. If Jewish people do go into those offices, too, then they require mezuzos. R’ Aharon Aryeh Schechter and R’ Uri Auerbach (Pischei Shearim 286:59) write that this applies to a carer’s room, too. Therefore, one would only need to affix a meuza if they have access to the room, too.
In conclusion, one does not need to fix a mezuza to a non-Jewish carer’s room that one has no access to.