Simple 1 cent plastic spacer difference between false alarm or secure alarm

It is amazing at left is a simple set of magnetic switches sold and installed by the millions every year in the US  for the protection of doors being opened by burglars which opens or shorts the protective circuit activating the alarm  .It consists of a reed switch ,magnet , cover cap and in bottom of photo a spacer plate.
Up to 70+%  of all alarm installers and technicians can not properly tell you the purpose of the spacer plate and why it is in the package .
most will tell you its used to help align the contacts on the door WRONG.
Yes it can be used for this purpose but its real purpose is to be used behind the magnet part of the switch when it is used on steel doors to prevent the magnet from weakening over time as it attracts towards the steel door. Do not use the spacer properly and fail to install it and you will with in a few years start getting unexplained false alarms  as the magnet weakens.

Why do Installers and techs not know this? Very simple the same old answer  total and complete lack of training and education in our industry. Had any of these individuals bothered to go onto the manufacturers web sites and read the manufacturers instructions or go to a alarm system class you will find this is what this plate is intended for.
But how many times as I work on and take over systems the spacer plate is missing on a steel door.
Sad but true. Yet another example of why learning on the job is only beneficial when person teaching actually knows his stuff otherwise he is just turning out one dumb shit installer after the other.
Having false alarms from doors and no answers check to see if spacer plates where installed . If not remove the contact set and install a proper one with spacer plate.