Rabbi Sperling, an orthodox family, just moved to my street. Would it be ok if I craft a mezuzah case for them? I would use the wood from a fallen tree from their property. If the case has no window, should there be an inscription or on the front? Am is messing something up? I dont know; Im a gentile.

Shalom, Thank you for your question. What a lovely idea! What a lovely welcome to new neighbors. As for the rules of a mezuzah case. Yes, a non-Jew may make such a case. It must have a place in it to insert the mezuzah scroll (that I assume the Jewish family will provide). Some mezzuzot have a little window so as to be able to see the scroll inside. But this is not a requirement at all, and most cases do not have this window. If there was a window, one would be able to see the three letters that make up one of G-d’s names – Shadia. Because of this, some people have these letters drawn or engraved on their mezuzah cases (or the first letter “Shin”). But this too is not required, and many mezuzot do not have these letters on them. I would advise you to not put these letters on your case. I hope this is of some help, Blessings.