Unskilled Labor
  
Think: Congressmen.
Ok, we snark. Think: tomato pickers. Manual dirt-haulers. Unskilled labor is separately tracked. Why? Well, in part because it's often seasonally driven. Like...when you hear the government reports of "non-farm payroll" numbers, they're ex-ing out the unskilled laborers, because they cloud the real health (or lack thereof) of labor numbers in the economy.
Unskilled laborers in the modern era have become clouds of independent contractors you can find driving Uber and Lyft cars, delivering DoorDash items, being available for jobs via Craigslist, AngiesList, and TaskRabbit. The big "risk" in the category is that robots become even cheaper and even easier to manage. It'll be an extraordinarily long time before a neurosurgeon is replaced by a robot (though they'll use robotic tools in operations); it likely won't be all that long before truck drivers and ditch diggers are replaced, however.