I want to hang a couple light fixtures in the bathroom.. The thing is i need to put a box in a pre-existing wall.. Any ideas on what kind of box i can use and how i should go about doing it? The wires already there from an old light but there is no box. I know how to wire it and everything i just dont know what box i should use and how i should put the box into a pre-existing wall. Thank you.
You need to purchase those box which clamp to drywall only but not the stud... the trick is to cut the hole on the drywall at the right size, too big, it won't clamp... too small, it won't fit.. has to be at a perfect size.... it has to be cut carefully.. mistake cannot be fixed... HD sell those boxes.... it's concept is like when you do the screwing the stuff behind the wall expand and clamp the device in place... why I know ... cause I did it before... except cut the hole too big... and the box is loosen up there (shaking)... and I don't bother fixing it as it is for the cable TV... not electricity...
I have used the rework octagons before and i am not a fan of them. The ones I have used are only rated for 12 pounds. You will have to cut it perfect or it will not work.
Another option is to use a regular octagon with 2x4 on each side. Screw the 2x4 on the side of the ocatgon letting the octagon hang below the 2x4 by the thickness of your drywall. Do the same on the other side and then put the octagon in the whole and the 2x4 will hold it in place. This will probably only work if you have access from above, i.e an attic.