The answer to 'junction box gets hot' is that a hot junction box is often a sign of an electrical problem that requires professional attention. Potential causes include loose connections, too many wires, or an overloaded circuit. Symptoms may include the box feeling hot to the touch, sparks, or burning odors. While some basic troubleshooting may be possible, it's generally best to call an licensed electrician to diagnose and repair the issue safely.
Attempting to fix a hot junction box yourself can be dangerous and may result in further damage or even fire. Electrical work should only be performed by qualified professionals who can properly identify and address the root cause. They have the expertise and tools to thoroughly inspect the box, tighten connections, upgrade the circuit if needed, and ensure everything is up to code and functioning safely.