Is it permissible to purchase "Judaica" or what appears to be Judaica, Mezuzot for instance, from a non-Jewish vender?

Shalom, Thank you for your question. The major problem of buying a mezzuzah scroll from a non Jew is whether one can be certain that the mezzuzah they are buying is in fact a kosher mezuzah. This is very difficult to verify. Even if the non Jew themselves are completely honest, it is almost impossible for them to be able to know whether the mezzuzah they are selling is kosher or not. Even when buying from a Jew one needs to be certain that the seller is both honest and knowledgeable. For example, if the letters of the mezzuzah were not written in the correct order (because the scribe discovered a mistake and then went back to correct a letter he had previously written) then the mezzuzah is not kosher. It is impossible to be able to detect this by looking at the finished product. One must rely on the honesty of the scribe, and the seller. So, if the seller is not a religious and knowledge Jew it is very likely that they will be selling you (knowingly or through ignorance) a non kosher mezzuzah. You should only buy mezzuzot, tefillen and tzitzit from a reliable source. The mezzuzah case on the other hand has no issues of how it is made, and may be purchased from a non Jew. The same is true of a Menorah or Shabbat candle sticks. As long as these items are not made for another religion, and has no issues of being made for foreign worship, they may be made and purchased from anyone. (In fact many of such items are made overseas by non Jews). I recall many years ago when I was walking in the Old City of Jerusalem and saw some American tourists – who were traditional, but non religious Jews – buying a lovely mezzuzah cover in the Arab markets. Now the cover case of a mezuzah is not like the mezzuzah scroll, and is simply a lovely box to hold the holy mezzuzah scroll. As such it may be purchased from a non Jew, as we wrote above. The merchant wanting to make a good sale offered, for a few extra dollars to include in the deal the inside scroll of the mezzuzah. As I watched he went to his computer's printer and photocopied a fresh copy of a mezzuzah that he had on a piece of paper. Needless to say this is not kosher. (I had the uncomfortable job of informing the tourists that they would do better buying a kosher mezzuzah in a shop in Geulah or Mea Sharim – without upsetting the shop keeper, who probably had no idea that a photocopied scroll was not kosher, and thought he was helping them out, whilst making a deal). Blessings.