You could build a MIDI-controlled relay/light, but you'd have to click a button to send the MIDI command before recording. If you have to click something to turn on the light, that's a lot more trouble to build & set-up than simply wiring-up up a regular 'ol light switch.
I just finished an 8ch version last week, but as is I'm not aware of how to use if to for this case. 
The use of a switch for this is a non-option. My sessions are WAY too fast and even though I've probably logged 10,000 hours on Cubase I can keep up with few clients. My console, compressors, etc keep me VERY busy at work. I'm looking for an automated solution.
I think you need to use MMC? Midi machine code. This sends out a message for start,stop,ff,rr and song position.
Hmm! Now that sounds very, very interesting. Thanks! I'll look into it. If that does what I want I simply need a solid state relay. This project will be a breeze. (Famous last works. :D)
Brandon