Please read my entire post. I said, "Congress does have the power to regulate the commerce which occurs entirely within the confines of a single state if that commerce has a substantial effect on the interstate commerce that Congress is regulating.
If your intrastate activity is not substantially affecting some commerce that Congress is currently regulating, you're golden. This would leave out things like your own local radio station, private airport, railroad, things like that.
Right, but what commerce-related activity is there that could not somehow affect, or be construed as potentially affecting, interstate commerce? Name one commercial activity I could partake in and "be golden"?