Electrical Engineers work under you how arrogant are you so what are you trying to imply you know more about Electrics than them.

I have met many people like you, you sit and look at you time table have you meetings drink your tea but tell me how many buildings did you wire, test or electrically test and sign off?

A lamp is not an appliance?

Someone might bring a light fitting with a lamp attached but there not going to have a suitcase full of replacements. They will go to the local electrical store for a replacement lamp. Lamp fitting can run off off different voltages where as lamps can not. The only thing that can damage a lamp is a change in Voltage which takes us back to the supply.A drop in Voltage will dim the light an overload will burst the lamp.

What you would NOT know because your not an Electrician it is very easy to determine what the problem is with an Electrical Installation based on the circumstances and behaviour.