Besides wall damage you may be able to hear dripping coming from inside the wall.
Finding inside of wall from attic.
Squirrels need to be trapped so finding their access point is imperative.
If you need to find the wires inside your walls you ll probably want a non invasive way to look for them.
There are usually two openings far apart.
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.
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.
Clean the attic first and remove any mice droppings and nests that you can find.
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.
How to get rid of mice in attic with blown insulation is a little different than a regular attic because of the insulation.
When working from an attic space it will be significantly easier to access a wall space on the floor below by working either an interior wall or the exterior wall that is on the gable end of the structure.
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.