MOTM

Ok, so here's the question:

Is a VCA usable for CV as well as audio?  I sort of assumed it worked 
for CV... here's where it gets weird

If a VCA can be used for CV, then doesn't that mean I can use it for, 
well, just about anything?  Like I could run a small electric lamp 
through the VCA, and the signal would adjust the brightness?  Or 
adjust the speed of a fan?

Hmm.  If that's the case, what kind of power would be safe to run 
through it?  =]