Well, I've never seen illegal drugs in boxes before. I have, however, seen firearms being shipped to individuals without FFLs and booze being shipped without an adult sign. Not just wine either; beer and hard liquors, good times.
Not illegal, but I always get a big laugh whenever a damaged box of

s comes in. I saw one a month ago that had the girth of a soda can and was 9 inches long. WOW! lol