WCB and your painter!
I am not sure how this works in all provinces but in British Columbia we have Worksafe BC, which deals with our workers compensation.
If you have a individual or a company working at your house that is not covered by WCB and they get hurt your home insurance will have to cover the injuries. Keep in mind that not all businesses are required by WCB to have coverage. A sole proprietor doesn’t need it but if they have employees the employees need to be covered. Some companies get around this by hiring only sub contractors (sole proprietors by default) which means no one on the crew would have coverage.
Cover your bases and do your homework go to http://worksafebc.ca and request a clearance letter. It doesn’t take long to do and it’s worth it.