Is there anything I can/should do?

[js0000001]

I had some cards due in the mail. When I checked USPS tracking it says they were delivered a week ago.

I can't blame the seller.
If I contact USPS I can't believe I would have any luck

 

[mjsch]

Get in touch with your letter carrier, he or she might remember delivering a few packages to somewhere in your vicinity. If not, maybe give your neighbors a friendly call. I had three cards and various other mail wind up in the neighbor's box. Luckily he called me as soon as he checked his mail.

 

[rbadger]

Good luck getting your cards! I had a Strasburg auto "delivered" to another address and checked with the local postmaster. They don't recall delivering such a package. Luckily it was insured and I got the seller to file a "lost item" claim. The post office originally denied the claim, but both the seller and I appealed the decision and I got a refund (around $150) back in a check. I was lucky, I guess... Good luck, that's a tough one to fight.