Yes, I am. I am also registered at an address in the Gmina, though not there 100% of the year. I have noticed though that all previous candidates stood under one of the Political parties. Not sure I could join one, even if I actually wanted to.
You can always form your own electoral committee - but normally, in Poland, you would associate yourself with one of the bigger groupings locally while standing as an independent. For instance - I have a friend who stood for election in the gmina. He was independent, but he was on the list of the PSL. Most local elections will work this way.