You would get a bill, and if you received the package, you could prove that it was a brick, and you didn’t order it, and thus the customs declaration form signed by me was fraudulent and you would not be liable to pay the duties.
If the duties were particularly high (enough to bankrupt you) it would be held at the nearest port agreed upon, and you be notified to come pay the duties before it’s delivered. Again thats where you would be able to show it wasn’t an item you wanted. Or you could refuse it all together and it would be up to be me to pay to get it back.
If this were a bigger problem the freight carrier would work to identify me and bring charges of committing various fraud.
As an aside shipping goods DAP (vs DDP) is risky for this reason—if buyers aren’t made aware if additional shipping costs at time of delivery they may refuse to pay in which case the seller is responsible for paying to get their item back, including additional storage fees.