yeah, my parents' US home (which was originally my grandmother's) in the eastern half of the US has plaster-on-drywall construction.

it is a bitch and a half for hanging anything (just like plaster on lath), plus it screws up wifi.

Pro tip for finding a stud, if you have access to the bare floor -- stick a drywalling knife / spatula under the bottom trim and poke. you can find the studs that way, and then measure off since 16" is pretty common. Measuring off the edge of an electrical box can work too, but you have to figure out what side of the stud the box is on...