Convert 3.5" round workbox to outlet

[aragno]

From this revised info:
1) You are saying Jacket #1 is not the other end of Jacket#4? (If it isn't the same, then there is another box unaccounted for.)
2) Draw in the cabling/connections for the floodlight. Show the floodlight and whatever cable it is connected to.
3) Need voltage test repeated with both switches (labeled) put in the chart and tested for each switch position.

1) I don't definitely know that Jacket #1 is not the other end of Jacket #4. It seems that way but I can't tell. I don't have a long enough set of cables for my multi-meter to check continuity from one end to the other.

2) I am unsure how the floodlight is completely wired in and I tried to only include what I know.

3) I've test both switches in all positions and combinations, and the black wire in the ceiling.
Updated graphic to reflect these tests but not for the above 1 and 2 since I don't yet have anything concrete. I'm happy to prove one way or the other and update so we are all on the same page.

I’m thinking I misread post 26. It does look like power hits switch box first. So a GFCI there can work.

I suppose the downside to a GFCI breaker on this circuit is the circuit will be very sensitive to small milliamp fluctuations and may nuisance trip. is that correct?

 

[Shiftless]

I suppose the downside to a GFCI breaker on this circuit is the circuit will be very sensitive to small milliamp fluctuations and may nuisance trip. is that correct?

Yes
For example, I have heard that a refrigerator will sometimes trip them.

 

[mm08822]

Check if the black wire in jacket #1 goes to the floodlight switch or to wire nut #2.

Then disconnect the black wire of jacket #1 from the switch. Is the loose black wire from jacket#1 0v?

If it is 0v, do the voltage test again.

 

[dscheidt]

Yes
For example, I have heard that a refrigerator will sometimes trip them.

Any appliance that trips a gfci is defective. Fridges that are doing it are usually actively trying to kill you — the usual cause is the defrost heater is shorted to the chassis.

Nuisance tripping on gfci are really only a problem when there are long cables, or when there are lots of loads, each with very small leakage.

Some motor drives have problems, as you can read about in the recent VFD thread, but modern high quality gfci devices have better features for hf leaks. A breaker from the panel manufacturer should be good quality…