Thanx for your answers,

I also think the main starting point of the problem is the ballasts (the emission it self could be from wires or the tubes), I changed the ballasts to dimmable versions and the problem is seen as spikes when it is in "dimming mode", there were small tendencys before i changed the ballasts but not that big of a deal.

If i only use it for on / off then it's like the old ones, small tendencys, i guess the dimming state is not the best state to be in.

But the problem seems fairly easy to get rid of.

I have read that most ground probes seems to be directly connected to ground without a serial resistance, but i think i will go for something in the area of 1Mohm, this seems to get rid of my problem but it will not help me with faulty electrical stuff (but thats not the reason for it).