This happens to me all the time. We get so many Dish receivers sent to my store Via UPS, we get all the DISH Network shippments for everyone else in the neighborhood.
The UPS man assumes the receivers are ours because they boxes have the DISH Network logo on it.
I just give it back to my UPS driver and he delivers it to the correct address.
If you decide to keep it, it will eventually catch up with you and UPS will call you and ask for it because they do have a record of the exact address of where they dropped it off. I had UPS one day deliver a receiver that was susposed to go to another retailer that I absolutly hated. Considering that it was already paid for with a credit card, I just put it on the shelf in my back room. Sure enough a few weeks later my UPS driver came by asking for it and I ended up giving it to him so he would not get in trouble!