All mechanical switch contacts arc to some extent and do so each time
the switch is operated.  The period of repetition of operation usually
isn't of much consequence.  If your 10 ampere/125v microswitch is rated
for the horsepower of the vacuum pump's motor, then there should be no
problem, which is to say that the switch should carry an "hp" or motor
horsepower rating.  This will assure that the contacts will withstand
the inductive load presented by, say, a 1/4 horsepower motor.

If you're still concerned about the capabilities of the switch you
should use a small microswitch to operate either a mechanical or
solid-state relay.  A solid-state relay usually consists of a triac
with appropriate buffering and stuff to make it work well with an
inductive load.  There's nothing to arc in one of these, and they're
inexpensive.  I think Radio Shack sells small sizes of them.  You can
also use an electro-mechanical relay or (more properly) motor
contactor.  The larger motor contactors are immune to everything from
lightning strikes on down, but they can make a fair amount of racket
when they operate.

A local electrical (not electronic) supply house may be able to help
you further.

Mark Kinsler
Athens, Ohio, USA.
http://www.frognet.net/~kinsler