stripped microwave shells - radioactive? Naaaaw... prove it - skeptic here

I have a hard time believing that a stripped microwave would set off any type of radiation detector. A whole microwave, sure - maybe because of the Magnatron possibly (other dangerous hazards for the inside of that part as most people know) - but an empty shell...? Anyone have any actual proof besides word of mouth that these are really "radioactive", cause although I absolutely DO NOT claim to be an expert on the subject, I do know a little about it. To my knowledge the inside of a microwave is NOT radioactive when turned off and it does not "radiate" food to cook it - I can post links to articles that support that part of what I am saying.

If I am dead wrong and someone has proof that an empty stripped microwave shell is radioactive - great, I just learned something and would be sincerely grateful, otherwise I am skeptical. No way that he outside of a microwave would be radioactive because if so - they should reject stoves or any metal from kitchens or anything near microwaves - and people might should not have them in their homes or businesses.

I can believe that maybe some steel pipes can hold some naturally occurring radiation depending on what they were used for (scale build up etc..), and there are other sources of radioactive scrap, but empty microwave shells?

Anyone?