It might be a setup, so I would look around carefully first, then take it. Now what to do with it after is the question. I like to think it's a little old lady that lost it and she is frantic to get it back so would wait for a post, or poster or something. On the other hand it might be drug money in which case it is free as long as you don't get caught with it then you would be dead. Some people take it to the cops and they have a nice dinner with it. Doubt I would do that.