When two naked wire having 240 volts on each touches there electric spark occur and at the same instant light surrounds it. So how that light form is this due to electron?
When the air gap between the wires becomes very small the electric field becomes very strong (1000 V/mm and more). This will accelerate the few ions and electrons in air so strong so when they impact the next molecule they will have enough speed to kick electrons out of it. This repeats and these many charges formed build a spark. Electrons and ions have opposite charge and attract each other. When they recombine their kinetic energy will be released as a photon, which is what you can see.
Also the contact surface of touching wires is very small, so a lot of current flows through a thin conductor there which has a high resistance and will heat up so much that metal evaporates and ionises from thermal collisions. Again, recombining electrons and metal ions will emit (visible and invisible) photons.