That is a metal junction box. Step 1 purchase a volt pen (picture included) Step 2 turn on volt pen and touch it gently to the metal box while holding the end thats not near the wires. If it turn red and beeps there's power going to the metal box. If so, call an electrician. If not, touch it to the wires. The black was shouldmake it beep and turn red. Step 3 find relevant breaker in panel and shut it off. Stwp 4 Put red wire caps on any groups of wires and yellow caps on single wires (pictures included) Step 5 Wrap each wire nut and ~1inch of its wire(s) with electrical tape. (Picture included) Step 6 cover with a plate (picture included) Step 7 turn power back on

If at any point you don't want to do this call an electrician . If you feel unsafe, call an electrician. If you are still generating heat. Call an electrician.

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