Quoted from terryb:While very dramatic, all that photo proves is the propellant, which quickly evaporates, is flammable. I could do the same thing with hairspray. This is not proof that the applied product is flammable (although it could be in the case of some cheap contact cleaners).
Here's the next picture in the series:
The Coin unit on the bottom panel of an EM Gottlieb that was sprayed with
contact cleaner. The game started a fire, burning all the wiring and the Coin unit
itself! This is just ONE reason why you don't want to use contact cleaner.
If this is going to be fixed, ALL the burnt cloth-covered wire in this area will
need to be replaced. Also the bakelite plates on the Coin unit will also probably
need to be replaced too, because they will be very brittle.