I want to change a standard overhead lighting fixture to a ceiling fan. Though I’ve never used them, I understand that brackets are available to provide stability without cutting into drywall. What do you know about them? Are they safe?
You're right to be concerned.. Most contemporary electrical boxes are made of plastic with two nails to secure them, and aren't nearly strong enough to support a spinning fan.
What you need here is an octagon ceiling fan electrical box with an old work bar hanger. With this little wonder, the bar is spread between the ceiling joists, and then the electrical box slides to wherever it needs to go.