led npn transistor switch?

[Prismseed]

So I'm looking at an led and there is an NPN in the circuit. I really wrested with why. Research makes me think that the NPN is used as a switch in the circuit so a cheaper/lower quality push button switch can be used, reducing manufacturing costs. Am I right or possible missing something?

 

[crutschow]

Without a schematic your guess is as good as mine.

 

[MikeMl]

Like Cruts says, but more likely the NPN implements the required constant-current circuit, as well as making possible to switch a higher current than the switch allows...