A number of paintball fields will also host airsoft games like CQB Paintball and Sgt. Splatter. Like L473ncy said, hit the Games Event Schedule for Ontario and you'll see when and where the games are, chime in and ask if an AV'er will be present, guys around here will help you and and hook you up.
"Hey I'm the first one to say its a great country but its a straaaaange culture. This is a place where gun store owners are given a list of stolen credit cards but not a list of CRIMINALS and MANIACS. And now they're thinking of banning toy guns...AND THEY'RE GONNA KEEP THE F**KING REAL ONES!"
-George Carlin 1937 - 2008 (RIP buddy)