Flicker start is a very common phenomenon in the conventional tube lights. However, the modern versions of tube lights (TL) and the compact fluorescent lamps (CFLs) do not exhibit this, but they start rather immediately on turning them on.

Both the tube lights and the CFLs work by the same principle. These lamps consist of a fluorescent phosphor coated glass tube filled with a mixture of the inert gas argon and mercury vapour. This gas is excited by the energetic electrons emitted from the cathodes provided at the ends of the tube.

These excited gas atoms interact with the phosphor material coated on the walls and we receive the light from this glowing phosphor material. Once this process is started, it sustains itself because both the excited gas atoms and the accompanying electrons are capable of repeating the excitation process further.

However, the initiation of the gas excitation is accomplished by extracting electrons from a heated cathode, by using an instantaneous high voltage pulse generated by a ballast circuit. The conventional TLs use a magnetic ballast circuit which makes use of self inductance of an iron core choke coil along with a discharge lamp type automatic starter switch to trigger the ballast.

And an inductance has a longer time constant and a resultant slower voltage build up for extraction of electrons from the cathode. These features of the ballast circuit often require more than one attempt for the gaseous excitation. This leads to slower start and start-up flickering of the tube lights. Because this arrangement has the above problems and also consumes more power, electronic ballasts have been subsequently developed which do not use the magnetic chokes, but employ semiconductor devices in an electronics circuit for the purpose and avoid the use of a discharge lamp type of starter switch.

They generate higher voltage to extract high energy electrons from the heated cathodes and so the extracted electrons excite the gas atoms without fail. Thus, these ballasts are called "rapid start ballasts" and do not exhibit delay or flickers of the lamp.

Tubelights are often observed to blink after turning it off. This can usually be observed when the surroundings are dark. If you observe the tube lights after you switch them off at night, there is a chance that you observe them blink for a long time.

Blinking of tube lights is an indication of bad wiring in your house. The wiring has been reversed entirely in relative positions of live(phase) and neutral. You can test it using your small electric tester. Test the electricity in any 3 pin socket - you will observe that the either left of right (of yourself) will show the presence of electric current. If the current is present in right part of socket, the circuitry is proper, if you find the left portion shows the LIVE current, your home circuitry is wrong.

Such wrong wiring can lessen your tubelight life.

This may not be taken so serious issue for electrical devices, but electronic devices will definitely be affected if used in such circuitry for a long time.