Electromagnetic, ferrous weapon(s) and materials attrector around the door

Electromagnetic, ferrous weapon(s) and materials attrector around the door. Or at a certain place.
(only if really needed, slightly dangerous for people entering while having ferrous metals like keys or while wearing steel work boots and or).
Might also be extremely dangerous for people who have ferrous metal(s) in their body.

for:
-So that all ferrous firearms and or melee weapons will be attracted towards the giant, extremely strong electromagnet.

Important: On and off switch.

Tests first.