Replacing motion sensor light

I am looking for some advice,

I recently moved into my GF's house and I am tackling a few repair projects for her because she has enough on her plate.
Our old motion sensor light broke, and our back yard is super dark, so I am replacing it.
Here are photos of the box on the side of the house (sorry for the bird poop)
and the new light and bracket. The bracket and light housing both have a green ground screw for mounting a ground, however there is no ground in the junction box.
I am assuming I have to have this light grounded? If so;
I cannot drill new holes in the house and I want to avoid having to run a ground wire along the outside of the house, is there a way i can ground this avoiding those two methods?
Thanks for an info in advance

 

There might be a ground in the cable already, but not brought into the box.

There are two issues to be addressed first, one that box is for dry locations only, and two those cables or wires need to be in a connector or a conduit into the back of the box.

 

Welcome to the forums!

To add to what pcboss said, do you know what type of cable the wires are in? Many metal-clad cable types use the metal sheath for ground. Or are the wires in conduit?

Adding your city to your profile will help us envision what might have been done where you are.

 

Agree. Take that box off the house and see what's behind it. If there's a recessed box behind it, just attach the mounting plate to that. If there's no box, you'll have to install a proper one. You can also get one of these with a flat back, they are listed as a junction box.

 

Thanks for the information guys, on a side note, is it ok to use electricians tape to tape the 120v wires together and then use the plastic/metal twist on caps over that?
I am in STL missouri btw..

 

No tape should be needed when you use wire nuts.

 

I have tried 3 different size wire nuts, and the light does not work, when i use electricians tape, then a wire nut over it, the light works. Should I assume I am just not wire nutting it properly? I have tried 5 different times and the mosquitos are eating me alive!

 

On the contrary, that would isolate the conductive metal screw from the wires it is covering. The wires should be spliced and trimmed, and the wire nut threaded onto that splice. No tape.

A lovely town. Could you please put that in your profile?

 

Yes. See what I said earlier. Extended version:

 

Is it unsafe for me to use electricians tape to securute the black to black and white to white wires? Or is it ok?

 

No,you have to use wire nuts,you can use tape around the wire nuts but it isn't necessary.

 

Be sure you aren't using "fake" wire nuts. Many times I have seen alleged wire nuts included with cheap lighting fixtures that had no wire spring in them.

 

Even 'fake' wirenuts are threaded. Unless he twisted them so hard they stripped, but I don't think thats the case.

 

Are you in the City or the County? Just curious. The orange wire nuts in the picture appear to be Ideal 73B wire nuts (or equivalents), get new ones like that and they should work fine. Don't try to use the old ones, you can probably get a small package of them in a big box store. Follow the instructions on the package. I wouldn't use tape on them at all, it's not necessary.