Does Shielding "Electrically" shield "Magnetically" too?
You would not be alone in this one. This is an often misunderstood phenomenon.

Static magnetic fields can not be shielded. They can be re-directed using ferrous materials but even those will not block them.

Electric fields on the other hand can be. Since an electric field is basically a voltage in space, they can not pass through a conductive plate that is held at a fixed potential. Space is shorted out as it were.

Alternating magnetic fields of sufficient frequency however, will not pass through a metal plate. The alternating field generates an eddy current in the plate which generates a cancelling magnetic field.

This is all explained in much better detail here.. Wikipedia