The post man delivered the wrong package to my house and i opened it !! can i get in tourble and will they kno?

okay the post man delievered the wrong package to my house and i didnt read who is it for so i just opened it since my sister and mom buys alot of stuff online anyways now am kinda scared since the package isnt urs and everything and i opened it will the post office know they delievered the wrong package to my house ?? will they come back and take it back?? cuz i cant give it to the ppl since the writing part is all messed up hheeeelllllpppppp anyone please tell me they know they delievered to the wrong house oo and when i got it i didnt sign anything they just dropped it on my doorstep