Tear the sheet across the width instead of tearing it lengthwise.
Running wires in insulated ceiling no attic.
Running electric across a ceiling sometimes requires you to enter into the attic but if you are lucky enough you may just be able to run the cable across the ceiling without setting foot in insulation.
Cold cobweb filled crawl spaces damp basements and tight attics are all just a part of the job.
Running electrical wire through the channel between ceiling joists is generally easiest.
First you can tear or cut the insulation sheets in half and lay half behind the wire and half in front.
Worst can you open the ceiling 5 inches from the wall and work from there.
There are two ways to insulate around wires.
In addition your light fixture may require mounting to a ceiling joist or to two short blocks nailed.
Here is how to fish wire through a ceiling.
For vertical work you can cut about 6 inches below the wall ceiling joint drill through the top plat and then fish from the opening ion the ceiling.
Locate the wall studs with a stud finder in the area where you re snaking your wires.
On a single story home or the the upper floor of a multiple story home this means accessing your attic to run wire.
If the wire is too tight to the wall to make that easy you have a second option.