He got kicked out of the building where he was doing his internship for changing the screensaver on the computer they were using to watch the training session.

electrical engineering high school might mean the German "Hochschule", so college or university.

It was not University but high school (15-18yo). In Slovakia we have gymnasiums (for students who want to go to university), trade schools (plumbing, machining, cooking, etc) and then also high schools with specializations (e.g. electronics, accounting, transportation), we were drilling Kirchoff since day 1.