Based on your recent comments, it’s right in your own backyard! Formerly and currently unincorporated DuPage and Kane counties. It seems that you have to build a new street inside an established municipality for those houses to get “normal” addresses.

FYI, I went to college in the 90s with a kid that lived in a rural area in a very low population county in Indiana (one stop light in the entire county). His house still had the old rural route addressing (your address was the box where you received mail - potentially miles away - and not a street address as commonly understood https://pe.usps.com/text/pub28/28c2_021.htm).