If you can’t pull a cable and are dependant on wi-fi, but still want a cable at the end point, buy a wi-fi bridge. You can see it as a switch that you can connect your stuff to with cables, but the connection between the bridge and the router/access point will be wireless, wi-fi.

Your computers won’t know they are using a wireless connection.

Alternatively, if you have an extra, unused ethernet interface on a computer that is already connected to the internet, you can share internet through that interface, making your computer a bridge.

This can be accomplished with an android phone and a usb ethernet adapter too. Though you might want a usb hub or split cable for charging.

Should also be easy to acomplish on windows. At least it was on windows 7, when I last used it.