Polling electrical wiring expert !!!
If so....was your original wiring knob and tube? (Different type of hole and clamp in your original box)....also different method of pulling new wiring.
Run a steel snake up through the hole in the box...you should be able to work this through the insulation.
Small hole in the ceiling joist (original hole for conductors)? Get up in the attic and cut the hole large...maybe 2 holes next to each other and chisel out the wood between the holes thus giving you some 'working space' to get that snake up through the joist and into the attic. It is almost mandatory to have a buddy up in the attic with a flashlight to give you feedback when working the snake and also working at getting the snake through the hole.
The easiest way to do this is to use a remodel type box and cut the hole to fit the box first (Don't cut where a stud is). Then drill a hole in the attic (be careful not to come outside the wall) and push the wire down to the hole (You may have to push a stiff rod or fish tape down first). Then install the box and switch
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OK, let's take this discussion a little further and identify the AWG size, box fill rules, the clamping to the box, type of box, termination of the EGC on the device, and compliance with the new rules for re-identification of the white wire if a 2wire/with ground was used, then grounding of metal cover plates, etc...