You then took that clicker to your local arcade, and clicked one of the corners of the CRT, that would send a shock through the system and add credits to your game. I believe this was because the CRT was grounded on the same ground lines that the mechanism for physically checking a coin had gone through the system.
Suffice to say, they caught onto this over time, and added some form of an alarm into it. But up until then... Those were truly the best times.
The "Jungle Jive" version of this would dispense tokens out the opposite side of the machine if the electric ignition of a cigarette lighter was used to lightly shock the metal intake slot. If you clicked it too much too quickly it would go into an alert mode. While this could be accomplished solo, the ideal MVP setup was a team of three: one scout to watch for employees, one to click, and one to collect.