How do I switch from Wi-Fi to Ethernet cables?

You can get a modem that uses a SIM Card, park it right next to your gear.

There’s no good adaptor solution that is better than your current set up.  Besides hiring an electrician to run a new cable for you I encourage you to find a Wifi analyzer for your phone or laptop to check the signal strength and also make sure you are an uncongested channel. Also, use 5GHz instead of 2 GHz if you have a strong enough signal. Fewer people use it and it has better bandwidth.

Keep in mind that audio requires very little bandwidth. A good wifi signal has many times more bandwidth than you’ll need unless you have many other users in the home.

IMO, even if you pour a bunch of money in your wifi, it will not be as stable as a wired connection.  Follow @cleeds advice and get a bid.  

I’ve been using Wifi and carefully analyzing it’s behavior and performance for both audio and video streaming, and I think this is a little unfair:

IMO, even if you pour a bunch of money in your wifi, it will not be as stable as a wired connection.

It really depends on a lot of things, like how congested your wifi neighborhood is, and where exactly your router is and the quality of the signal. I live in the burbs and I can easily do wifi for audio or video here. 4 other competing signals and 4 bars of signal strength. In my San Francisco apartment though, I couldn’t stream anything. :D

I do generally agree that those are the only two options:  Optimize the router channel and placements, and have a hard wire run.  The latter of course is best. :)

I think you want a nice set of wifi6 mesh routers. I have had good luck with ASUS AiMesh equipment.

That not only would solve your concern with the Node but would benefit all other wifi devices you have or may purchase in the future.

There are also power line adapters that plug into the electrical outlet and provide an ethernet connection if you are trying to connect just one specific device that is out of range of your wifi.