I had an interview similar to this. I'm a programmer, but I had just taken an intro to circuit design course at my local maker space, and I emailed the instructor about what potential jobs would be like day to day, if I got into more electrical engineer and circuit design. He emailed back that he knew a friend at a company that designed motorized kid's toys, so he could set up a meet and greet. He emails both of us, we set a time to meet at the company.
I get there, and they think I'm there to interview for a programming job. Instead of explaining the confusion, that I was only there to learn more about the day to day of the electrical engineers, I roll with it and just decide to do the interview and see how it goes, as I was unhappy in my current job and was looking to make a change anyway.
Big. Mistake. Interview goes horribly since I hadn't prepared, and as I'm leaving after having obviously failed the interview, the one engineer who interviewed me says:
"Hey, um.. We printed your resume on some high quality paper, do you want to keep it?"
Only time I've been handed my own resume back to me in an interview.
Also the guy that I had originally set up the meet and greet with turned out to a be a bit of a jerk in the interview process so I never bothered explaining the confusion and trying to get what I had originally wanted out of visiting that day.