Can voltage in a run of outlets/lights be reduced to the point it lights a test lamp, but not enough to light a 4 watt bulb? Below is a description of my problem:

I have a run of three outlets (maybe other receptacles too) that ends with a ceiling light receptacle in the basement. The light stopped working, and my mom asked me to put a new light receptacle in. I did, but the light still did not work (bulb is good, fuse is good).

I saw an outlet that feeds the light receptacle, and tested for current at that outlet. My test lamp lit up when I inserted the prongs in to the hot and neutral slots. What was odd was my mom got a small candle light (with about a 4w type nightlite bulb in it) - and it would not glow! So it looks to me like there is just a trickle of voltage - enough to light the test lamp (which I guess has to be like a 1/10th of a watt), but not enough to light the higher 4 watt bulb (or the 100 W bulb in the light receptacle).

At least 3 outlets in front of that light receptacle also show this reduced voltage. What would cause this? How would I test?

The other thing I tested was the ground at the outlet that feeds the light receptacle (at the end of the line). I don't know if the receptacle is grounded properly, or has anything to do with the low voltage, but this is what I found.

When the low voltage was present at the outlet, my test light lit up when I put on probe in the hot slot and the other in the round ground slot(but not the other neutral slot, so I thought it was properly grounded). Then I pulled the off/on chain at the new light receptacle, and saw the outlets in front of it would not light my test lamp. Also, at the same time that these outlets did not show power on the test lamp - both the hot slot and the neutral slot tested like they were both grounded! Is that correct?

Is it possible that trying to turn on the light bulb at the light receptacle could "suck" the little voltage past the outlets in front of it to the point that they would not then be able to even light my test lamp?

I'm no genious with this stuff, so be gentle please. But I would appreciate any insight as to what may be wrond, and how I can test and correct this for my mom.

Thanks, Matt