Son in Law's house -

Kitchen ceiling lights, Living area ceiling fan / light, entry way light, front porch light all not working. They are on the same circuit / breaker with two other ceiling lights that do turn on.

Main breaker never tripped, with my limited knowledge - switches show current getting to them. Do not see a GFCI outlet associated with this area.

Problem seemed to start after unplugging outside Christmas lights from porch fixture / plug.

The problem is with only the one breaker.

One of the wires that feed the next fixture/plug may have come loose on the porch fixture/plug. Open it up and see if all the wires are still connected and tight.

I would open up the outlets where the Christmas lights were plugged into. The problem is more than likely a loose neutral wire ( white wire). If the wires are pushed into the back of the outlet , turn off the breaker and put them under the screws. After time the pushed in wires can become loose and not make a good connection. If it is not there then I would open any other outlets that have been used a lot and check there.m

It appears there is an outlet inside of front door that is labeled GFCI but does not have a reset button on it. I guess there is an associated outlet with reset somewhere on that circuit that is tripped.

When the GFCI would trip in the kitchen of one of the houses we've recently live in, I had to reset it out in the garage.

Hope you find the source. Good luck.

What's the verdict?

We have a hidden GFCi outlet. It’s in a storage closet, on the outside of the house, where you’d never expect it to be or think to look. It’s for a room inside that’s nowhere near that closet. I’m guessing something similar is your problem. I’d look where the Christmas decorations were stored.

I have never seen a GFCI without a reset. What you are saying sounds like a homemade label for a "down line" protected receptacle.

If that is the case then you just need to find the GFCI that is the protection, or that is beginning, of this circuit.

If nothing else, have you flipped and reset all of your breakers? Sometimes they may not looked tripped, but may be. I know that with all of the electronics that can be PIA. Just get past that.

i have a gfci in my master bath that the plug on the front porch is on. 40' away. messed with me for a tad.

Yup. My money is on a GFCI receptacle being tripped. My old house had several outlets controlled by one GFCI receptacle. Frustrating for sure.

Update:

He spent the majority of the week checking all GFCI outlets, nothing tripped. Saturday evening, checked breaker box for a dedicated "reset" - none. He did turn breakers associated with GFCI circuits "Off" then back "On". No change.

Last night lights on affected circuit started working ...........

That would scare the heck out of me, and I would keep looking until I found out why!!! Go back to the receptacle the X-Mas lights were plugged into, put another load on it and see what happens. If nothing else, I would short out the receptacle, go find the tripped GFCI or breaker, and replace with new!!

Yeah, breakers go bad sometimes, IME.

Yep, that just screams loose connection in one of the boxes.

Had same problem but non GFI breaker. Ended up being a loose wire in a wall plug that was in line with some light fixtures and other plugs.

Had same issue - loose wire in wall box. Turned off breaker, reinserted wire and voila - power.

from your bolded above, me thinks a loose (series) neutral on a socket, or even at the breaker panel. Tighten up all the neutrals in the breaker panel.