I took apart a "Magic Lights." It is a wind-up laser top.
Internal Pic:

There is a speaker that makes laser sounds, a red laser, and 4 LEDs.
My questions are:
What is the switch? Is it one of the blue things? There is no on/off switch, it just turned on when it was spun.
Closeup of main circuit board

Is the laser even worthwhile? I know it fell off, that can be easily re-soldered, but is a laser on a Nerf gun just stupid?
Laser closeup

That is all.