How can I safely install outdoor wire for lights in my backyard?

To safely install outdoor wire for lights in your backyard, follow these steps:

1. Use outdoor-rated wire that is suitable for the environment.
2. Dig a trench at least 18 inches deep to bury the wire.
3. Use waterproof connectors and junction boxes to protect the wire connections.
4. Keep the wire away from water sources and sharp objects.
5. Test the wire before burying it to ensure it is working properly.
6. Consider hiring a professional electrician for complex installations.