Everybody knows you can produce electrostatic charge rubbing two different materials together. But have you ever smelt e.g. at the plastic after charging it? There actually is a distinct electrostatic charge smell :-) While normally smelling involves the transport of molecules, what you are smelling here, is the electric field itself, or do you? What is happening?
The charge on the object ionizes the air a little. I believe that you smell some combination of that and reaction products (such as ozone) from ionized air.