Duplicating same content in different URLs

Lets say that I have a page that offers house cleaning services in California.

Now I take that entire page and I change every mention from California to Florida, including ALT tags, URL, headings and other stuff. The rest of the content remains the same, since the service is the same.

I do that for 1.000 different URLs: am I getting punished in some way?

Would it help if I add some kind of 300 words spinned paragraph for each URL?

From my experience, you might get those pages to index but there is a good chance you will see the lose the indexing if you don't create unique content for those pages. There is also a good chance they don't index.