I recently sent a postcard out that was supposed to go to the Netherlands with a .94 cent stamp.  I had my return address on it, and I received it in the mail today!  No return to sender or anything, they just delivered to the return address instead of the correct address.  In fact, it only took 1 day!

Should I be able to take it to the PO, show them their mistake and should they then deliver it correctly w/o me paying again?

I don't know how it could get confused - I wrote the addressees address right under "Send to:" preprinted on the postcard.

Thanks!

Yes you can actually just drop it back in the mail!  Be sure to look for any barcodes that may have been added to the postcard (front and back) and either remove or obliterate them.  If you actually take it in, they may be able to give you some idea of why it came back to you - I can't see the addresses, so I can't comment on that!

Those barcodes on the picture side of your postcard will be really hard to see (unless you've been lucky enough to have the barcode sprayed on a strip of removable tape.) They're orange lines and unfortunately, if they aren't obliterated, your postcard stands a really good chance of being returned to you again!

Chances are the optical readers that spray on delivery barcodes picked up your address as the delivery address and your carrier didn't catch the mistake at delivery.