If you enjoy working in construction and prefer working on utility cables and pipes, then becoming an underground locator may be the right career path for you. You will use equipment to locate new spaces to lay new lines or to detect pre-existing utility work for repair purposes, testing, or to avoid severing wires.
In order to get contractor work in this field, you must first be familiar with the equipment needed to locate the underground pipes and cables. Most utilities give out frequencies, which the locator will measure to get an idea of wire or water drain placement. You can also measure electric current direction, especially with things like fiber optic cables, and verify the depth of any sewer or septic pipe system. Frequencies can bounce from one piece to the next, making it also simple to detect gas lines and buried manhole covers.
Training for this construction site oriented position can usually be found via apprenticeship under someone already in the industry. Many contacts can be located online who are willing to train those interested, but for a price. Since you'll not only need the technical knowledge, but also the physical experience of leading the drill to the proper boring spot, it's well worth the investment. A proper trainer will show you how to excavate, build a trench, and pull old pieces for repairs while taking care not to penetrate work that doesn't need it. It may be wise to also train as a lineman, so you can see how the cables are laid. It's not necessary to the position, but it may help you have a better understanding of the job.