FlexWatt Help

[Will]

So I'm cleaning all the shelves tonight and I start hearing this buzzing sound when wiping off the heat tape. Turns out that when I put my hand across the heat tape I can hear a faint buzzing sound, kinda like the sound a current would make. This was somewhat troubling. Probably not the safest way to find this out, but it makes no electrical "buzzy" feeling when I do this, but if the room is totally quiet and you put your ear right next to the tape, you can hear this buzzing. I'm sure I can hear it, although it is really faint.

I'll describe what I have, but I've also got photos, since those are more useful. I connected the tape using O-ring connectors and drilling a screw into the melamine shelves. I completely sealed the screws in silcone sealant and taped everything up - both ends of the flexwatt. The flexwatt is held down using foil tape, and the thing is, is that the sound only occurs when touching the 2 strips of foil tape, not when touching the two sides that aren't covered in foil tape. Is it possible for the foil to be drawing a current through the flexwatt's plastic coating...? I covered over the flexwatt's metal conductor strips, even though there shouldn't be anything exposed there, but it still buzzed when I put foil tape back on. I double checked all possible exposed ends(don't worry, I unplugged it all first ) and made sure the foil tape was nowhere near anything that could be exposed, and made sure the plug connection was totally insulated and still with the buzzing...

I dug out a digital multimeter, but I haven't played with one of those since Grade 12 Physics, and I really question my focus in that class to begin with. I played with all the settings, but got some sort of reading on only one of those settings, so I snapped a pic of it, figuring someone here'll know what that means

Anyways, here's some photos, maybe someone here can help...

Here's the whole length of shelf. Again, I can only hear the buzz when I touch the two sides of foil tape, and I only got the reading on the mutimeter on the foil, not the other uncovered strips.


Here is a closeup of the plug connection with most of the elecrical tape taken off.


Photo of the multimeter. I played with most setting and in various spots. This was the only reading I got. Again, I can't feel anything, but could hear a buzz, so I dug this out to give me something else to work with.


This is kind of dark, and I'm not sure if this helps any, but here is exactly how the rubbermaid sits on the shelf. It only covers 1/2 of the tape.