Smile! You may be on Candid Camera

I am convinced the post office in my small town is messing with me.

When I receive a package that is too large for my post office mailbox, I receive a key in my small box for a large lock box that holds my bigger package - 
similar to this one...

Easy enough to see that you need to obtain your package from locker #18, right?

 

 

 

Twice now, in the last two weeks, I have received a key like this one in my mailbox for parcel pickup...

After the second time (yesterday), I almost looked around for the hidden cameras, as I started trying to unlock random lockers, hoping my un-labled little key will fit one of them. Do they really not see the problem with continuing to use and un-labled key? Or do they really just not care that I have better things to do with my time than stand around going from locker to locker trying to find one that matches my key???