People are assigning names to components I've never even heard of! It's called a Neutral Safety Switch people! The switch will not let the vehicle start unless it is in Park or Neutral! On manual transmission models, it is called the Clutch safety switch or Clutch interlock switch or whatever! on many models the switch is located on the transmission where the shift linkage/cable goes to the shift arm on the transmission! some of the switches can be aligned with a drill bit! get a Chilton's or Haynes repair manual or find the procedure online. In the Park position a drill bit can be inserted in a hole in the switch, which aligns the switches electric contacts to connect only when the gears are disengaged in Park or Neutral position! The switch is usually attached with 2 bolts, 1 pivot, 1 adjuster! If this switch is good but slightly out of adjustment they can cause an intermittent starting problem! Engine vibration over time can sometimes cause any bolted on accessory to loosen, and
these switches loosen sometimes! I've adjusted many after finding them loose and cars will start right up! I've also replaced many of them and solved the starting problem! It is an electrical switch and they do burn out with time like any other electrical component! People have broken the bank replacing starters, batteries, alternators, relays, solenoids, the list goes on, and then called me to actually fix the problem! And it can quite often be an overlooked component in the starting circuit. #1 get a vehicle specific Repair Manual for Your vehicle! Read the section on the starting circuit and understand the many components in it. Models vary! it may be a highly worn switch on the steering column under the dash that is actuated by a rod pushed by your key cylinder! Looking online is a stab in the dark, everybody has an idea of what they "THINK" it is, and that gets expensive fast! If you do it yourself get a Manual and test, test, test!