Gonk,

A couple internet searches led me to some info on plemum rated wire. From what I've read, it is only required when wires enter an air duct (common in a commercial building). The outside coating on plenum rated wire burns at a higher temp an therefore does not send toxic gas into the HVAC system if it were to burn.

Why would plenum rated wire be required in a regular household wall? Something I'm missing? I ask becuase I'm getting ready to run some wire to my surrounds.