Car will not start when key is turned to start position Battery is at Full charge and the idiot lights come on what is the problem I think it is a faulty switch but I'm just quessing, would that be a correct guess?

Turn ON headlights and try to start car.

Headlights stay lit, no change in brightness means an open relay.
Start car in Neutral, or move gear shift in and out of Park and try to start in Park; otherwise it is the ignition relay switch or the starter solenoid.

Headlights dim slightly: Low battery charge

Headlights dim significantly or shut off completely: Battery cable connections are really dirty. Remove cables from battery and clean cable clamps and battery posts. You may not need to boost to start.

Hope this helps!

The yearbook answer is you should have the car checked by someone with an enhanced ford capable scantool. The starters are not uncommon failures in a focus, and all fords have had issues with the PATS keys (factory keys which have a theft system chip in them). If your anti-theft light starts flashing after you try and crank or while you are cranking, or stays forever on after you turn the key to run position, you may have a theft system or failed key problem. As usual, have it checked...or if you have the original spare coded key, switch to your other key and see if that allows starting

It could be a faulty ignition switch but it's rare for them to fail.
More likely to be either a wire off the starter motor or a faulty solenoid.
If the car is automatic it could be the inhibitor switch which stops the car srarting while in gear.
All are fairly easy to check for a diy mechanic if you know someone.