Oren wrote:
....
I have asked myself; if there might be and "illegal" electrical box
inside the wall that burnt, but it seems the OP has no
breaker/electrical problems (unless I missed it)

I will really enjoy what the true cause is; given all the replies!
....

Yeah, I wondered similar thoughts but it seems too new for that to be
likely -- of course, nothing can be ruled out of what _might_ have been
done...

That's where I think until he at least cuts the Tyvek to see what the
sheathing looks like in general there's nothing more to be learned.

And, unless the damage is then shown to be other than totally
superficial (and it'll be obvious if it's inside-out instead of
outside-in), I think the obvious has to be something put some heat out
there in that location whether he knows what it was or not...the grill
pushed out of the way after use of something similar is really still the
most likely culprit in my view--

It's possible will never know. But, as you say if there were something
untoward inside, looking at the sheathing will be able to show whether
it came from inside and if so, then opening up the wall would be the answer.

Why he seems so reluctant to go ahead and dig in and uncover the mystery
area directly instead of bandying about here is beyond my ken...the area
needs to be repaired anyway, so it's not like he's doing anything
drastic in cutting out an area of Tyvek...

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