The U.S. is full of them since we have a service economy, meaning many corporations are based on providing a service. Some techs will go to people's homes to repair washing machines, TVs and VCRs. Others might work on exercise equipment in gyms. Some will repair high-tech printers and plotters in offices. You might specialize in the repair of industrial equipment like conveyors, presses, or assemblers.
Some companies do only field service work.
They send their techs to many different training classes to allow them to work on many types of equipment. As you can see, there is about any type of work environment you might desire in field service. I was an honor student in school. I took many advanced math and science classes. When representatives from the area vocational-technical school came to talk to ninth and tenth graders, I decided to take electronics over the next two years.