This is for posters in Ontario or those who might visit here.
A flashing green light on a private vehicle in Ontario is a Volunteer Fireman responding to an emergency call.
Although most in the country know this the urban dwellers do not, in most cases, and visitors will not.
It is not in the Drivers Handbook nor is it taught at most driving schools.
For some reason our Govt. will not allow Volunteer Firefighters to use red lights on their personal vehicles.

So if you see someone with a flashing green light, in Ontario, please get out of the way.

It may be your house on fire or a friend or relative with a medical emergency.
Practically all rural Fire Depts. have Rescue trucks and many firefighters are darn near paramedics and some actually are.
Remember these people have to get to the Firehall before the rigs can roll!
My township has 3 small towns, several small communities, 4 firehalls but not one full time Firefighter.