How about a strong magnet hang it in the closet, put a piece of steel
in the trap door.



Ha ! great minds think alike ! fools seldom differ

I was just now looking-up strong magnets - they make them to lift
a few hundred pounds - for salvaging stuff from rivers & lakes ..
but they don't seem to have any "release" mechanism ..

just one example :

http://tinyurl.com/yy55s2az

Not sure what thickness of flooring it would lift 10 - 20 pounds
through ? Easy to experiment on scrap wood pieces ..
It would allow the hidey-hole to remain invisible ..
.. to the narcs :-) but not their dogs ...
John T.