Disconnect the battery, which you should do anyway when replacing an ignition. There will then be no danger of it inflating.
When the headlights are on or the key is in the ignition.
Nothing to worry about just disconnect the negative battery cable before you start and then you can't hurt anything.
The ignition switch is where you insert your key to start car
If your headlights, horn and everything work, I would have the ignition switch checked out. Make sure you checked all ingition fuses and relays first.
Have you tried replacing the PCV valve?
Not sure on a zx2. On an Escort LX it is behind the fuse box in the engine compartment.
The ignition switch is in the steering column..that's where you insert the key to start the vehicle.
This is something that is almost impossible. If this is happening on your Ford Escort you have some serious wiring problems.
your best bet is to have a locksmith come and remove it this will avoid any damage to the locking mechanism and save you from replacing your lock
ask your local car thief
Disconnect everything and pull it out if it is like a manual 1991 ford escort
find where the horn is and pull the wires off it