Ok, here is an update. The junction box in question is a single splice (wire nuts, hot, neutral, ground), and the feed leading away from it is killed off at another junction box about 15' away (gray ROMEX?). So, the feed out of it is going nowhere.I traced the breaker to a 20 amp circuit which is currently powering a series of lights, both inside and outside; a porch light, two garage side lamps, two flood lights, and interior ceiling light, and one 5' run of track lighting. it appears as though the cord feeding the junction box is coming up from out of a wall, along with several others, right above where there is a quad switch
plate controlling the aforementioned lights. I have not yet checked the voltage, as I do not have a multi-meter; I will pick one up.So, given the new information, provided the voltage is 120V, can I replace the existing junction box in question (which is dead) with an outlet? If so, I presume it would need to be 20amp? Also, would I want to use a GFCI or just a standard? It's a given that I would replace the existing JB with an appropriate new-work receptacle box; metal or plastic? What I am trying to power, at this point anyway, is one (1) security camera.