Here is a stupid question that will show my ignorance of the topic. I am working on a project, and i have a small sleeve to feed part of the system. The question is can I run two leads of 12/2 to the sleeve and then run a large gage wire through the sleeve that returns to two separate 12/2's?? Probably not but I thought I would ask before I bore 25'. If it is possible what gage wire would I need.