HawaiianRain has some good advice.
Once I had a package not have my street address on it... so obviously, no slip. But tracking said it had been attempted delivery (no, because no street address). But I was sooo lucky, I went down to the post office in person and they checked the back for me. Showed them my ID, and that was proof enough. They kept it around for a few days because it was sent EMS and they figured I might showed up.
I guess put in your zipcode and the word post office in google, and it'll probably come up with the post office that your package might be at-- with the address, and zipcode. At least, that's where you could start.
Or ask a neighbor? Or whomever is in charge of the place you are living at...