Can a judgement be placed against me for a credit card bill that has been charged off and closed?
A judgement can be placed against a debtor for a charged off debt. That's because a "charge off" is basically a creditor's way of informing a credit reporting agency that this is a bad debt. The fact is that in such an event, a creditor can no longer hold a debt as an "asset" on its books (money owed is considered an asset for the creditor) because a debtor has defaulted on payment.
That having been said, a charge off does not negate the fact you still owe the creditor the moneyin question. Accordingly, your creditor may hire a third party collection agency to collect from you or your creditor may simply sell your debt to a third party, who in turn then has the legal right to attempt to collect from you. Either of these situations can include suing you in court and obtaining a judgement.
Note: Every state has a "statute of limitations"'; this is the timeframe in which a creditor can sue on a debt. Depneding on the state, typically a creditor has between 3-10 years after a debtor defaults, to bring suit. After that time, the statute has run so a creditor is time barred from pursuing legal action against a debtor (although the debtor still technically owes the debt).