I thought about returning his call, but I do not see what that will accomplish. They are not going to mail it to me. My answering machine doesn't give my name or telephone number, so they don't know I ever got their message.
After I got the call yesterday, I checked the Internet and there has been a scam going around the US where someone calls pretending to be a USPS employee looking for valuable information. I checked on the return number and it is legit and the shipment was mailed in LA where this man called from, but a careful person most likely wouldn't return the call anyway.
I'm still thinking that I need to ignore it.