This is a searchable sight that Pauline sent.
Just wanted to add if you are unable to find him on this site
National Archives of Canada
from my genalogy group the price is around $5.00 $7.00 Canadian Dollars
This way does take awhile ! Another option, you do not need a researcher
The more you have on your relative the better age when enlisting, place
of birth next of kin etc.
Mary from Surrey BC Canada