I would suggest a seperate micro switch (mains rated) attached to the back
of the saw so when the saw is slid forward the switch operates or it could
be attached to the part where the saw tilts down and is operated, this would
need a flexible lead though. I know it's obvious but make sure all bare wire
are enclosed in a proper shroud so there is no possibility of you or your
saw comng into contact with the wiring. The micro switch should interrupt
the path of the "live" to a socket that the extractor is plugged into.
Ideally you should have an isolator that will kill the power to the whole
sawbench when you are not present.

Rgds Al

.. "Michael Billings" wrote in message
news:GKszd.14068$uj2.11284@clgrps12...
I have a Bosch 3915 Sliding miter saw. I'm bolting it to nice bench with
support wings. In base of the bench I want to have storage as well as a
shop Vac. directly hooked up to the saw. Ideally, I want to be able to
turn on the saw and have the shop Vac function at the same time
(automatically). Is there a way to do this without major wire modification
on the saw? Thanks.

Michael B.