Super handy to have. A strong magnet is better than any stud finder imo. Just sweep it across the wall until it sticks to the screws that are attaching the drywall to the studs.

Also great for sticking things to walls without damage. There’s a privacy curtain in my bedroom doorway for example: Let’s me keep the door open for my cat to come visit, while maintaining a private space in a shared apartment.

(there’s usually a steel reinforcing strip at the corners of drywall sheets)