On Sun, 8 Sep 2019 06:44:13 -0700 (PDT), trader_4
wrote:

On Sunday, September 8, 2019 at 1:44:05 AM UTC-4, Bill H. wrote:
I have single light switch, three romex in ceiling box, TWO LED panel lights
are running out of ceiling box. I want to add TWO more LED drop in panels.
I need to know HOW to add these.
Breaker Box turns off electrical outlet, stairs, BOTH LED lights, AND
additional lights in other basement room.
HELP PLEASE!

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Assuming you want the new ones to operate off the same switch, then you
wire them in parallel with the existing light, connecting black to black,
white to white, bare ground wire to bare ground wire. Where you connect
into the exisiting wiring depends on where the new ones are going and
how the existing has been run. Most times you'd connect at the existing
box for the light fixture that's there.

Next issue is how many wires are already in that box and how many it's
allowed to have per code. Typically they accommodate 6 to 10, there
are wire fill tables that show how many wires are allowed for the common
box sizes. You have three romex going in already, if they are each two
conductors, then that's 3x2 conductors + 1 ground =7. If you add another romex to
go to the first new light, that would make it 9. So that box is
supposed to accommodate at least nine 14g wires, assuming it is 14g.
Find the max count in the tables for your box, as long as it's 9 or
more, you're OK. Romex goes into old box, run over to first new box,
daisy chain to next one. Buy old work boxes for the new spots, they
are made to install into existing ceilings.

The typical 4" octagon box used for ceiling lights is 1 1/2" deep and
is full with 7 conductors. (3 14g Romex)
If by remote chance they used a 2 1/8" deep box, it holds 10 14g.
conductors.

http://gfretwell.com/electrical/Box%20fill%20table.jpg