"..2. DEFINITIONS. For the purposes of this section:
a. "Dangerous Weapon" means any device designed as a weapon
and capable of producing death or great bodily harm, ... or any other
device or instrumentality which, in the manner it is used or intended
to be used, is calculated or likely to produce death or great bodily harm.
The following are dangerous per se: ... any other knife having a blade
3 inches or longer. Instruments not herein specifically enumerated are
none the less considered weapons when they fall within the terms of
this definition.
Note: "Instruments not herein specifically enumerated" can include smaller knives than 3 inches...."
So basically anything is a weapon in WI, to include car keys.