A junction box is the small case where wires are joined safely. Fit a junction box, hidden junction box, trace it back to the junction box.
The joint has to be inside a box so that a loose connection cannot start a fire in a wall. A junction box must stay reachable, which is why burying one under plaster is against the rules.
1nounjunction boxThe small case where wires are joined safely.
“The fault was a loose wire in a junction box above the ceiling.”
junction box is a fitting.
Practised in Tools & DIY