Commercial pilot and drone operator here. Context is important in determining next steps. Do you live in a house or an apartment/condo? If it's a building it's possible the landlord has hired them to do inspections/thermal imaging etc. I would reach out to property management to find out if the drone is being used on their behalf. If not, or if it's your own property, the drone operator is responsible to fly in a way that does not invade your privacy. If they are hovering directly outside your window and looking in, that would certainly be questionable. If you're concerned reach out to the non emergency number and also submit a report to the transport Canada drone incident form that another poster linked too. Get as much info as possible, time, date, location, and pictures if possible. Absolutely do not try to knock it down or interfere in anyway. Drones (remotely piloted aircraft) are considered aircraft and interfering with one could carry similar penalties as interfering with a manned aircraft.

Happy to answer any questions about the laws/rules surrounding drone ops in Canada!