If you opt to collect your Swiss Post package at a Swiss Post service point, make sure to have the Swiss Post tracking number with you (to show to the agent proof of notification by email or by SMS) and also to have your ID card or another official form of identification.
If you can't go to the service point in person, you can ask one of your family members to go instead. The person who is representing you will need to also have the Swiss Post tracking number with them and carry an ID.