Not going much into detail. There are three housemates. X, Y, Z.
X had something sent under Y. Success. A few scores of days pass.
Sheriff comes to door, leaves card with name & Y's name written on it.
Neither Y nor Z have knowledge.
What is X's solution?
Can note be ignored? House cleared?
If it was pack related, you would have never had "success" and they would have givin you a "special delivery".
Have Y call the pigs, it's not a crime to see what they want. If they want you to come in for something, LAWYER UP! Don't answer any questions over the phone and make sure you say directly that you'll answer no questions regarding anything without the presence of legal council.
But I wouldn't stress about your pack if you've already got it.