Hmmm ... I can see the quandry you face. It's an excellent opportunity for bringing the theremin to the attention of many more people ... but not necessarily in a way you feel comfortable with.
The media have pigeon-hole mentality, and are only able to visualize a theremin segment in a "spooky" context. I certainly don't think that thereminists should take themselves or their music too seriously ... but give them an inch and they'll take a yard, shifting you from spooky music, to spooky voice/laughter, and probably end up with you drenched in fake blood if you don't draw the line early on!
Perhaps a compromise: do 5 seconds of "spooky" sound effects, talk briefly about how the theremin was used in old sci-fi and horror films, but then say that since Hollywood hijacked the theremin in the 50's its versatility as an instrument has been sadly overlooked; then show just how wonderful it CAN sound ... easy, with your fabulous theremin!
Don't agree to anything that will make you cringe when it finally airs ... or you're likely to regret it. And, above all, remember that whatever you say/do during the interview, they'll probably edit into something you scarcely recognise with all manner of "spooky" camera effects.
Personally, I'd rather rip out my left eyeball and feed it to a small dog!