FTR the switch might well be a low voltage switch from the fireplace ignitor (if you were thinking of tapping power from there).
Mark Kessler is a great local electrician who has gotten many a good review on here (I’ve used him for years and referred him many times as well)
Kessler Electric 206 409 7046
more recommendations here
https://westseattleblog.com/forum/topic/electrician-recommendation