Good packed, and arrived on time, Light is nice and bright,works very well when u have only one on/off switch in the circle,(220v) i have 3 on/off switches in one circle (220v) they change pole.. and when lights are turned off, one corn bulb is flashing every 15 seconds..
As others have said it's induced voltage or what is sometimes called phantom voltage i but it also means that when 2 wires lie next to each other for any length and one is live, it will induce a voltage in the other one
It isn't usually a problem because the runs are usually short so the voltage is very low,
These are very low wattage bulbs and I think there's just enough voltage to charge up the choke/capacitor or whatever starts them, and get a flash.
overall bulbs are tested and fine for use with simple circle with one switch and all works fine.