This might be one of the smallest underground homes conceived and constructed. As you can see it fits him quite nicely and he’s written a ebook about it too. See and read more about Dan and his tiny home at Moonlight Chronicles!
The Hobbit Home of Dan Price

How is it he has electricity in his hobbit hole. The picture shows a lit lamp, and there’s another behind his head.
I assume a micro off-grid system… battery, solar panel, etc. It doesn’t take much to light lamps.