Try ringing a bell in vacuum, you won't hear a thing! That's because waves need a medium. Can I assume that since there is vaccum ( a low pressure or a very less number of particles or matter), hence there are no particles thats why we are unable to hear i.e. there is nothing like a wave but we assume.
I have studied that EM waves have both electric and magnetic field components. These components oscillate at right angles to each other and to the direction of propagation, and are in phase with each other.
Since light is an electromagnetic wave, it is not affected by travelling through static electric or magnetic fields in a linear medium such as a vacuum. In nonlinear media such as some crystals, however, interactions can occur between light and static electric and magnetic fields - these interactions include the Faraday effect and the Kerr effect.