The answer to 'why is my junction box flickering lights' is that a flickering junction box is often caused by a loose connection or faulty wiring within the box. This can allow electricity to arc and create a flickering effect in the lights connected to that junction box.
Some common causes include loose wire connections, a failing electrical component like a switch or outlet, or water damage inside the junction box. Symptoms may include flickering, dimming, or pulsing lights. To fix the issue, you'll need to inspect the junction box, tighten any loose connections, and potentially replace faulty components. If you're not comfortable working with electrical systems, it's best to call a licensed electrician to diagnose and repair the problem safely.