Make sure you aren't accidentally setting the DTEC's ctype while drawing that wire.
One way to confirm that it's not the DTEC that's sparking the wire and it's something else is to hover your cursor over it (over DTEC) and monitor the .life property, it should read 0 and not 1 if DTEC's ctype element is not within its detection range.
It it reads 1 then make sure you have its detection range set properly and not to some high numbers.
Lastly, I would suggest making a save and linking it here so that me (or any other user) can see what's exactly happening.
DTEC works fine for me so it must be something else.