A pinhole camera is a small, light-tight can or box with a black interior and a tiny hole in the center of one end.
You can use anything that has a tight-fitting top – a clean paint can, a vegetable shortening can, a 2-pound coffee can, a shoebox, or even a cylindrical oatmeal box.
To make the can light-tight, paint the inside with dull black paint or line it with black paper to prevent light reflections. If the can you use has a plastic lid, paint the lid black.
Be sure to paint it inside and out; then before using it, check to make sure no paint has chipped off. Chipped or peeling paint on the lid will allow light to enter the camera and ruin your pictures.
Make a small hole and you’re done.