[header] How to install shiplap [title] Find the vertical studs behind the drywall. [step] Run an electronic stud finder horizontally along the wall until you can locate the studs. The stud finder will flash an led bulb or emit a beeping sound when it's placed over a stud. 
Work slowly so that you can be precise, and aim to mark the exact center of each stud. [substeps] Use a pencil to place a light mark at the center of each stud.