No, you aren't obligated to pay support to anyone so the state can't garnish an account only bearing your name. Your wife owes child support, not you, you are not responsible for her support obligations.

Even so, the state can't attach retirement accounts, anyway. If you deposit the funds into a checking account you hold jointly with your wife, that may be how the state can get the money. You may want to get a separate checking of your own.

Not to worry - the money you take out of your 401(k) will NOT be subject to your wife's late child support payments to someone else. The 401(k) is in your name, not hers. Only items in her name might be subject to garnishment for child support payments in arrears.