How can I get an annulment in the state of Pennsylvania if not Catholic?

I have been married for only one month. We got married in a wedding chapel and not a church. My wife has shown me that she is mentally unstable and has papers to prove it. I have been working away from home and we see each other on weekends only 4 to 6 days a month and we both believe that we've made a mistake and want out of this.