My first job out of college was a small ISP. I did odd jobs, whatever needed doing.
I handled billing of past due accounts, Web design, last mile wireless installations, dialup tech support. All kinds of stuff.
There were a few contenders for the worst parts of the job.
One time, for a wireless installation, I had to crawl under a grain elevator which may or may not have been housing killer spiders/raccoons/spiderracoons. I was a complete mess after that, needed several showers. On a similar gig I got attacked by wasps on a roof.
Dialup tech support tried ones patience mightily. But was basically predictable.
Web design was rubbish. I will never do that again. Clients are morons, who somehow think they know what they want (because they surf the net a lot), while having no idea what they want.
But the worst was the insurance company up the hall whose owners were bored a lot. At first, it was just the middle aged sister of the owners who would stop by to play with my long hair (awkward, but not super icky). But then, one of the owners decided I needed to sleep with his massage therapist, who had taken a shine to me. I had a long term girlfriend at the time, which he knew. I told him very plainly where I stood, but he would not let it drop. Soon, she would come by as well to play with my hair. My boss thought this was the most hilarious thing ever.
Anyways, not long after I got a real job working in enterprise software. That owner and his massage therapist bizarrely are in jail and dead, respectively. Last I heard about the sister, she had adopted a baby from Asia.