Bad Caliper or something elce?

Get the wheel off the ground and then apply the brake and release it then see if the wheel will turn. You will always hear a little contact noise when spinning the wheel but it shouldnt be dragging.The first thing to check is if the caliper slides are sticking and not letting the caliper float. I dont know how your caliper is retained but they all use some sort of slide or pin arrangement to let the caliper float. They become dirty/corroded and hang up. The next thing to look for is caliper piston sticking. The seal inside the caliper is of a square design. Its not of a round design like an "O" ring. When the fluid pushes against the piston it moves out and slightly deflects or drags the seal with it. When the brake pressure is released the seal wants to deflect back in and pull the piston away from the pad. Its not much movement, only thousandths of an inch but its enough that the pads are not rubbing all the time. It does what a spring would do on a shoe type brake system.
Sticking /rusted/corrosion is especially true on equipment that is seasonal. Best thing for equipment/cars/trucks is to use them, not let them sit.