I was not properly served a summons
I was sharing a house with a couple of other people in California, I moved out in July 2007 and some how even though I no longer resided there, and was never notified of the court case at all, the owner still got a judgement against me in Nov 2007. I had no idea I was even being sued or had been sued, I only found out that he had won a judgement against me through my credit check last week. I can prove that I was not living there at the time. Any advice on how to proceed ?