No, your wages cannot be garnished to satisfy your husband's back child support. However, you may wish to consult with a tax professional re: filing married separately, in order to avoid garnishing of tax refunds that may be due to you in the future.
No they cannot garnish your wages.
The other attorney is right - don't do anything with his social security number attached to you -- that includes --
buying a house
opening a bank account (checking & savings)
filing tax returns
You need to keep all of your finances separate!
You will need to keep written proof (paperwork) that you have kept all of your fiances separate. It your YOUR responsibility to be able to prove that you have kept your property separate.
You might want to do a PRENUPTIAL AGREEMENT before you marry then excute a POSTNUPTIAL AGREEMENT after you marry to confirm that you really meant to keep all of your finances separate.
Therefore, even if you marry you are going to act like you are single.
You might not want to marry this man. Just live with him. It's simplier. Sorry!