It might even be against your credit card policy to intentionally attempt spending beyond your limit (if the account is valid). And if the account is closed, then you intentionally offer it for a purchase (and every NYOP offer is a purchase contract), it seems to me that would count as attempted fraud. So either way, it's not something I'd recommend.
Better idea: 1. Use a prepaid anonymous gift visa/mc/amex card with no or little money on it, or, 2.Use any random number that conforms to the mod-10 algorithm (you can easily come up with your own if you google anatomy of credit card numbers). Any expiration date and cvv number is fine.