A little help here?

What kind of switches?

 

Those kinds of switches are hard to do. Well to start this is not realy practical. you would be better using the door switch to put a node in the ground so when they step on it they die. If you are into a splatter switch then you have to put a powerup somewere with a crate behind it and a man cannon behind that. (there are many posts of these already so if you don't understand search in aestetic maps switches).
If you truly want the pressure plate idea this is how you would do it, but let me tell you a few problems first. It has one use and takes a second to activate. Also it would be huge. Ok this is how you do it. first interlock to make a pallet sized hole. Then put a nod below it to support it. (not on) then put a fusion coil below it with a weapon holder to support it loosly. where the fusion coil falls you put a man cannon. the man cannon directs the fusion coil into a gravity lift. You have a second gravity lift with place at start no and 180 respawn, run time minnimum 1. This will cause the gravity lift to spawn. The rest is oblivious you put a crate in front. it pushes the crate and the crate falls.
Long, difficult, delayed, and after 180 seconds it goes off anyway.
here is a diagram hop it helps.
............-------------
...........l........B<G.l
...........l...._______l
...........l....l
.
............P
......___,,,,,___
......___F....___
......___''....___
......___.....___
-----___.....___
G.........<M.....l
_____________

 

.___.
|[C]|
.{P}
[][][]

"P" is a powerup, this could be a custom powerup with no effect.
C is the crate. Red Lines are Immovable objects.

The powerup is holding the crate in place. The powerup could be on a stand of some sort, which would raise the powerup, and possibly conceal the plate.

When the player touches the powerup, nothing is holding the Crate up, and it falls.

 

or you could do the dumpster door switch on Foundry.

 

I know a really simple switch method, its for spawning a grav lift at a location to move a door/elavator...etc
(however this is really only good for casual maps as it is Really simple)

first you get a grav lift and place it somewhere to act as your button...
(you will need to set it to never respawn)

Then place a second grav lift to suit whatever your trying to move
(set this to not respawn at the start)

Now all you have to do is set the run time Maximum for the grav lifts to 1 and start a new round...

Now shoot/blow up your 1st grav lift and the other will respawn moving whatever you put in front of it.

Like i said not a great method but great for getting started lol
Hope it helps.