Stud finder could detect studs or copper piping
My dad once had the bright idea to cut a big hole in the bathroom wall to install cabinets set into the wall. He found a huge toilet pipe behind the toilet. Below the toilet is the sewer pipe and the water pipe to go into the tank/bowl. Above and behind the toilet is a vent pipe that goes up and eventually out the roof. You can hang cabinets.just NOT into the pipes. Try lighter cabinets with those mounting screws.
PVC and water piping can be behind walls in a single story or two story homes. In a both style homes, there are vents to every plumbing fixture. There will be pvc of 1.5,2 and even 3 inch pipes. These pipes are at times vents but, at times in a two story home are the drain for the upstairs rough and the water lines for your upstairs fixtures are also shooting up your walls and then routed through your ceiling. Be careful and good luck.
