Dimitrios Paskoudniakis wrote:

Ho do you trap a dead squirrel?

You don't.

You allow it to leave before you close up the hole.

It was already dead.

Not according to your original post:

=========
A squirrel made its way through an opening to the attic, then down the
interior of a wall in our master bedroom. We have since had an
exterminator company seal off the opening, but the squirrel died inside
the wall a few
days ago, and now the room smells.
=========

The order of events as you first described the situation indicate that
the squirrel died after the opening into your walls were sealed off.

Do you now want to tell us the truth, or do you want to spin another
version of this story?