Recently, all 10 Toronto History Museums became free! The website doesn't tell you this yet, but you have to go on a guided tour to see the house; you can't go through on your own. They are closed on Mondays and Tuesdays, but here are the opening dates and tour times:
Wednesday, Friday: 12:15, 1:15, 2:15, 3:15, 4:00
Thursday: 12:15, 1:15, 2:15, 3:15, 4:15, 5:15, 6:00
Saturday, Sunday: 11:15, 12:15, 1:00, 1:45, 2:30, 3:15, 4:00
Tours are limited and do have a capacity. Arrive early to avoid disappointment (at least 30-45 minutes before your desired tour time). The gardens are also STUNNING, so bring a picnic. The grounds are open till 5 pm Wed, Fri, Sat, and Sun, and till 7 pm on Thursdays.