I live in a building that isn’t in an eruv area. Is there any way in which I am permitted to take or place something from the hallway into the apartment (or vice versa), like a paper or a bag, on Shabbat? (Would staying physically in one "space," but only reaching by hand into the other space, make a difference?) Thank you!

Shalom, Thank you for your question. You are correct in thinking that there is a problem in transferring objects from your apartment to the stairwell (and vice versa) on Shabbat in a location without an eruv. For more information on this you should see Shmirat Shabbat KeHilchatah, chapter 27: 11-18 (also available in English). This is forbidden even if you just reach your hand out to the hallway (as you suggest) – the object cannot be moved from one domain to the other. However, there is one case where this restriction does not apply, and also a way to organize a halachic solution where it does apply. In a building with only one Jewish religious family then this restriction does not apply. See Shulchan Aruch, Orach Haim, 382,1. So, if in your apartment building (which itself is an enclosed domain) you are the only religious Jew, you are allowed to transfer from the hallway to your apartment (and vice versa). If however there are other religious Jews in your building, it will be forbidden to transfer into and out of your apartment unless you make an "eruv chazarot". Such an "eruv" is a halachic means of joining all the private domains into one domain, so as to allow transferring between them. This is a little tricky to do as it involves some technicality. May I suggest that if you decide to try and make such an "eruv" you get in contact with a local Rabbi who will perhaps be able to help you more than I can in this short internet format. If you have further questions, please do not hesitate to write to us again. Blessings.