If a house goes to foreclosure, then all parties lose their interest in the property. I would suggest you contact a real estate attorney to help you sort through the reality of your situation. I fear that you may find that you are now living in the bank's home.
I personally wouldn't do anything until you are contacted by the foreclosing lender. They may offer you something called "cash for keys". In essence, they may offer to pay you a sum of money to help you move out.
But like I said, I think you should contact a R/E Attorney first to go over your situation and options.
If the house is in foreclosure, no matter how many owners there are, everyone loses their interest in the property. You can't foreclose on half a house. Please get a bit clearer and people here can help.
Best advice, find a real estate attorney.