Sir BPmax . . .
CONSIDERATIONS . . .
Tell me if that electrical outlet at the bottom is prepped in the same manner as the last outlet we worked with.
Meaning, that the top outlet has the breakout tab broken out , thus leaving no power connection between the two hot side screws ?
You plug a lamp in at the bottom outlet and all switching and light functions are being normal.
NOW . . .
You plug a floor lamp into the top outlet and fully expect it not to work . . . . BECAUSE . . . the switch up above it has been repurposed,
with it now wired to activate some later day added, light cannister additions in that same ceiling. They work fine.
So o o o o o . . . I am now seeing that re marked red painted wire as being a formerly "hot" switched wiring line and the white being the companion neutral for powering that now functioning bottom outlet.
BUT . . . that black wire connected to the top screw terminal is disappearing into the flex conduit and making a travel all the way to its end where it is expectedly disconnected /cut / taped off
BUT . . . . for a goodly portion of its run, it is being right up against and "kissing" a hot wire, albeit, there is just their wire insulation separation.
What is happening now is there being a combinational electrostatic and capacitive coupling between ACTUAL "HOT" wire and the floating black wire wherein an AC voltage is induced into that floating black wire.
Then your 'lil dinky lite indicates a voltage presence on it . . . if floating and unloaded.
You then flip on the lamp switch and the once existant voltage plummets to zeeeero by that lamp resistance totally pulling down its feeble induced ELECTROSTATIC voltage.
BECAUSE . . . . that induced ELECTROSTATIC voltage has no current / power ooooompth behind it.
The "HOT" wire has enough DYNAMIC voltage with its combined current /power to run a vacuum cleaner or electric iron from its outlet.
And thats the way I see the situation . . . . .
73's de Edd . . . . .
Did ya' ever think that perhaps your whole purpose in life is simply to serve as being an ample warning to others.
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