MiamiCuse wrote:
....
very strong odor ... attic...like some dead animal ...
I am not sure how I can fix it. ...
... is not something for an exterminator? or is this
another profession altogether?

Undoubtedly got a squirrel, 'possum or some other critter or bird, and
yes, you had best take care of it as promptly as possible.

Some extermination companies may be willing to tackle it, that would
probably be best place to start if you're not up to taking care of it
yourself. Might call local animal control office and ask for
suggestions -- they probably won't do it, but likely can tell you who
could/would.

As an aside, near here at the local knacker's, the sign includes the
message

"Your used cow dealer".

OBTW, once you've gotten the particular problem resolved, look
carefully for signs of where it made entrance and for other signs of
long-term habitation/infestation and resolve any such issues or the
problem is likely to recur.