I ran ethernet from our basement to a couple of bedrooms by passing the lines through where plumbing goes to the attic for the soil pipe vent.
Finding inside of wall from attic.
There are usually two openings far apart.
Use interior walls only.
Besides wall damage you may be able to hear dripping coming from inside the wall.
All holes around the edge of the attic need sealing with mesh wire screwed with screws to prevent mice from coming back.
If you notice any of these signs try using a moisture meter which can be bought at your local hardware store.
How to get rid of mice in attic with blown insulation is a little different than a regular attic because of the insulation.
Clean the attic first and remove any mice droppings and nests that you can find.
To use it scan the device over the wall to find the area that has the highest moisture reading which will be where the leak is coming from.
After all without a method to your madness you d just be hammering unsightly holes through your drywall in a vain attempt to cross paths with your wires.
For the mouse baiting in the attic and the basement should do the trick along with finding and securing the outside opening to ensure more won t find their way in.
Squirrels need to be trapped so finding their access point is imperative.