What do you do if you get a package delivered to your address but to someone who does not live there?

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My daughter is away living in an apartment for College. She got a package delivered to her from UPS, signed for it and assumed it was something addressed to her. It's not uncommon for her to get packages since she lives far away from home. After opening it she noticed it was some really nice stuff and looked who it was from. She then noticed it was her address but someone elses name was on it. It could be the person that lived there before her, who knows. What do you do? Do you call UPS and tell them to send it back to the company and that you already opened it. Not to be selfish but she doesn't want to pay any money to ship it back. It's not like the mail where you put return to sender, but I don't believe they even take something after it's been opened.