How does radon get in the house?

It’s a difficult thing to work long hours on the job just to be able to afford a Summer home down  south. Maybe for people in fields such as management or finance, it’s not difficult to purchase a second home.  I don’t earn a huge salary, however. I own a handful of coffee shops that started out as a single, local shop eighteen years ago.  It’s been one continuous struggle for my wife, Amy and I. We are happy with what we do and we’ve done well. Amy and I have worked hard to build up the business to the point where we can get away for half of the year.  She and I bought a little Summer place down south where we can escape the cold and snow of the Winter seasons that we deal with up north. We are fortunate to have the opportunity to do this and I really shouldn’t complain about any of the little problems we experience.  Amy and I have recently had a concern with radon gas. The land on which our Summer house is built can sometimes shift around. There are never any large earthquakes, but now and then we’ll feel small tremors here and there. One of these tremors definitely shifted the foundation of our home sufficiently to cause a crack in the foundation. The  radon gas detector in the basement was beeping when Amy and I arrived last winter. I ended up paying a professional radon mitigation service to handle the issue. The professional handled the radon concern and now the home is safe once again.