If I found a lottery ticket, at the begining I don't know if it won a prize or not, because here in Spain you must look the lottery number in the newspapers the day of the play, or look for in internet that there will be the numbers and then you can "comprobar" if you are the winner or not.
Although if it the winner ticket, I didn't return the moey to its owner if I don't know who is the owner. And of couse I don't put the advice in a newspaper because I will never know if the person that say that he or she is the owner, I can't "comprobar".
Good luck!