Window Sensors

[DigitalPimp <mark.stubblefield@xxxxxxxxx>]

Hello Everyone:
I'm trying to figure out what sensors to get for all of my windows.
It seems when the pre-wire was done all of the holes that were drilled
into the window were 1/2" and have a cap that has a hook inside that
holds the pre-wire.  The other issue is the holes are directly below
every single window's seal that runs across the bottom of the pane
that moves up and down.  The window seal is sort of silver looking and
is rectangular shaped.  The seal is about 1/4" thick on the short side
of the rectangle and about 3/8" wide on the wide side of the
rectangle.  So I have 2 questions:

1.  Does a 3/8" sensor fit into a 1/2" hole?  Is it OK to get a button
type magnet and somehow affix it to the seal on the bottom of the
window with glue or the like?

2.  Should I use pressure type switches for the window?  What can you
recommend?  I have a feeling that since the sensor will be under the
seal, it would be easy to insert something from outside and bypass the
sensor by holding it down when opening the window.  This part worries
me.


On a side note, all of the doors were pre-drilled at 1/2" as well.
Most of the doors have the holes at the top of the door (inside the
door frame) and one has it on the side where the door handle is (yet
again inside the door frame).  All of the doors are metal but one.
What should I do for this?  I've seen the roller ball type switches,
but also read they are prone to clogging.  I like the wheel ones, but
haven't read many comments about them.

TIA
-Mark