If a strange package shows up at your door twice, never assume it belongs to you, then decide to hit the road with it. It could very well be a large quantity of marijuana.
A package appeared at the doorstep of a Florida couple's Louisiana rental home over the summer, so they returned it to UPS. When it returned to their doorstep once more, they took it inside, forgetting about it until it was time to return to Florida. They finally opened it, discovering two suitcases which, for some reason, they assumed belonged to them.
They elected to open the suitcases once they got back to Florida, ultimately discovering 11 pounds of weed, which they turned over to police. If you're going to open a mysterious package, at least check it before traveling with it.