well hmm...
makes me wonder a whole lot of things about that interconnect scheme. If there's a transformer in there, then there should be virtualy no DC current flowing to the mic, at least not nearly enough to power it. I'm with you, I wouldn't send it 48V until I knew it was made for it (sounds like it's not).
That's definitely a confusing situation.
Is there any kind of pre-amplifier in the mic itself? Any electronics at all? An electret needs power not to charge the plate (it's permanently polarized), but to power a buffer or preamplifier in the electret cartridge. A modern electret cartridge such as those in common cheap mics (Behringer ECM8000 for example) has a little FET built into the mic that requires power to operate. However without the FET, there is potentially some signal coming from the mic, albeit a very small amount.
So maybe this electret element you have is large and sensitive enough to produce some useful output without any buffer or preamplifier.
???
that's very odd.
I wonder if someone in Klaus's forum would have a better answer than the cheapskates over here in Harv's world.