I got this idea about a week ago... And finally I found some time to write the script.
This script can create a cage - the parameters are size (X, Y, Z), number of divisions (X, Y, Z) and thickness of the 'wire'; the image below explains it all.
Important note: if you set the divisions to high values (maximum allowed is 16), the mesh will become very complex; A cage with 16x16x16 divisions consists of 5408 points and it can take several seconds to build the model, depending on your CPU speed. It shouldn't be too long and Anim8or shouldn't crash/freeze, but you never know... Also the non-uniform scale tool (which is normally used to change the X, Y or Z size of the cage) works very slowly when the number of divisions is too high. Be patient please...
However the script should work without any noticeable delay unless the number of divisions gets close to the maximum.
Image and script file attached below. Enjoy!