The chipmunk physics behavior has a way to get the point of collision, but other than that you'll have to calculate it yourself for anything else.
For one idea you could look here:
That capx has a way to calculate a normal. If you create an object at the ball, and then move it by the radius in direction of the normal with the "move at angle" action, then you should get a point of collision.
I'd make a capx but my pc seems to be dying bit by bit and C2 has been the latest victim. I'll see if a reboot helps.
For the absolute most precise way you could use the SAT (separating axis theorem) on the ball and wall. That's usually used for resolving a collision, but it can also give you the point of collision. I've made some capx's of it elsewhere on the forum.
Or you can do the math directly. Find the formula for the distance between a point and a line and use it to find the distances to the four lines of the box, only check that the point if projected on it land within the segment, then find the distances from the four corners. The closest of any of those will be the one you use to get the normal and collision point.
I've done both before, and they work well although can be a bit complex to setup. An approximation is usually good enough as with the first idea.