Marshall - 4:01 pm on Oct 22, 2012 (gmt 0)
Tell the seller that you reserve the right to keep the merchandise...
This is the root of all the FTC recommendations on items received that were not ordered. The recipient is under no obligation to cooperate with you and you cannot file a criminal complaint or small claims action as the error was yours. The only time you could pursue legal action is if the package is taken by a third party, such as in it was delivered to the wrong address or they stole it from the address it was delivered to.
Bottom line - You got something you did not order. You could be nice and return it, but you are not legally required to do so and, as the shipper, there is nothing actionable you can do about it.