Bought a polymer 80 kit for a fun little build project. However a mistake occered with my order and the vendor has it so a signature is required. Not big deal, but the package is going to come when I'm at work. I have a brother who's 17 and was wondering if I could let him over to sign for it. I'm 25 and I'm the one who's going to build it, he's not going to be involved in that in any way, but I just want to save myself a trip to the post office to pick it up if I'm not there. Will USPS not let him sign for it if he's not 18 or 21, I looked every where and couldn't find any info on the topic.