There's no definite answer to your question because you might get caught, or you might not. If the person writing your paper shares your information with your professor or college, you'll get caught. However, most essay writing services don't share your information with anyone else, including the person writing your essay. This means your chances of getting caught are very low.
I've worked with many essay writing services as a writer and editor, and we ensure the student's information is only shared with the writer. I also help students write college papers as a tutor and have never shared their information with anyone. In short, make sure you trust the person you're asking to write your essay and agree to keep it private.