A common credit myth is that a divorce decree will absolve you from any credit obligations the judge decides your ex-spouse will be responsible for paying. However, the truth of the matter is often discovered the hard way when one spouse stops making the payments on time and the credit scores of both parties suffer.
The fact is the original contract with your creditor trumps everything, so you'll need to work directly with the lender and credit bureaus if you want your name removed from anything you and your spouse jointly signed.
If you haven't worked directly with the lender to address the issue, then you shouldn't be surprised when the mortgage for the house your spouse is now paying for still shows up on your personal credit report.