If that something had any value, it probably wasn't really "lost".
Once I had occasion to buy some equipment from a US postal employee. I met him at his place of “work”, in the basement of the local Federal Building where the postal operations were. This guy had a rather large makeshift office built of plywood on the warehouse floor. He had over 20 years seniority and he was retired on the job (must be nice).
His day was spent inside his “office”, which had shelves and shelves of magazines with the postal address labels still on them, addressed to various people who also thought their item was "lost" in the mail. He had a small TV, microwave and hotplate, several radios, and several different hobbyist computer systems (this was about 1980, when small computing was a hobby). I wondered if everything in there was purloined from postal customers, including the computer equipment he sold me for dirt cheap.
Maybe 20 year ago we did a promotion sending a free item to people who responded to an ad. Had 1000’s of responses. Along the way we started getting reports that people had received their package, but that it was empty, and that someone had cut open the package with a blade and slipped the item out, mailing only the empty envelope. One or two random events, couldn’t know whom to blame. But when we had scores and scores of the same exact complaint we knew it had to be happening from our local post office. Someone had to be slicing open the packages here and then sending the empties. We reported it to the local postmaster, of course we don’t know what was done but ultimately the problem stopped. I figure they fingered the culprit but who knows to what end, other than an end to thievery.