To build a really cheap paint box, you could use a large cardboard box, like a washing machine carton, remove 1 panel (front) and set it on a table. This would contain the over-spray, but you still would need an exhaust for the fumes. A piece of dryer-vent pipe going out the back at the top would pull away some fumes, but must be vented to the outside.
A step-up to a permanent paint booth would be the same thing, but made from plywood, still must be vented to the outside, a power bathroom exhaust with changeable filter would help and you could mount a small strip light in the top. The exhaust with filter would also be the best alternative for the environment.
My solution to the overspray and fume problem is to paint outside. It is a challenge in the winter and bad weather, but produces the best results with the least complaints from others in the house. I paint very little these days, so don't blame me for global warming. LOL