Dear Mr Hurley,
I'm writing to you because I have found some documents with your name on them.
While I was returning from my trip to Warsaw, I found your documents lying on the ground next to the bus stop near the bus station. As your address was in the documents, I decided to send it to you.
I see that you are a tourist, I hope you enjoyed your stay in Poland.
I am asking for feedback whether you received your documents.
Sincerely,
XYZ.
Mam nadzieję, że pomogłem!