Replacing porch light, but no ground wire from house

Black to red, white to white.

You have no ground available so leave it as the old fixture was unless you want to pull a ground from the house panel.

If it's an older house and the light and wiring were put into place before grounding was required by code, you can just replace it without ground by hooking up the white wire to white and red to black. If ground was required by code at the time and it was put in incorrectly, then it should be corrected by running a wire with ground to it.

Yes, it's a concrete block house almost 50 years old..

Thanks to both posters for the info.

white to white, red to black, forget the ground.

It is quite possible that the ground was, and hopefully is, provided by a conduit to the box. I would check that and assuming the box is grounded make sure the fixture is also properly grounded to the box.

If you have a white and red conductor from the house, it's not in a cable, therefore it must be in a conduit of some sort. If it's fifty years old, most likely that conduit will be metallic, and provides the grounding for the circuit. Connect the black to red, white to white and ground to the box or fixture bar which is screwed to the box.

If the electrical box is metal and the wiring comes into the box with armored cable (BX) or metal conduit, the grounding is provided by the metal jacket or the pipe. If this is the case you would ground the wire from the fixture to the metal box using a separate screw or a grounding clip.

You might want to consider installing a fixture that doesn't have any exposed metal parts. It will be marginally safer.

Obvioiusly, the best approach is to replace the cable with a grounding cable. Alternatively, you can install a GFCI on the circuit. This will provide protection against electrocution that's superior to that provided by a "proper" ground connection.

I have a motion sensor porch light that was installed prior to moving in the house. I took the porch light off and wires inside are all fried. I not sure what wires connected to what. There are 2 different cables that come into box. One cable has only 2 wires white and black that's connected to breaker box and the other cable has 3 wires red, black and white that's connected to inside double light switch how would I wire this porch light to light switch

It is hard to answer without more detail.

Did it work when you moved in?

Did anything in particular happen just before it broke?

By a "double light switch" do you mean two switches, at opposite ends of the hall, for example?

What is the black wire connected to now? the white?

In the other cable What is the black ire connected to now the white? the red?

I presume there are two wires coming from the lamp. What color is one and what's it connected to? What color is the other and what's it connected to?

It might be easiest to make a drawing, a schematic, photograph it and post the photo on an image sharing site. IIRC flickr is one.

So, I just leave it? no cap?

What are you replying to?

It would be best if you describe your particular situation from the beginning.

It sounds like the two conductor cable from the breaker is the feed. Then the other cable probably uses the black to connect back to the hot side of the switch and the red to connect to the other side of the switch. In which case, the two blacks would get connected together, the whites get connected together and to the white wire from the fixture and the red wire connects to the fixture black.

But not being there to test and probe this out, that's just a best guess. Odd that it could be so fried that what was connected to what could not be determined.

Odd that you are replying to a post from October 2020. ;-)

I hope he isn't still "in the dark" so to speak. ;-)