Whats the reaction that creates light when I open BreatheRight strips? Darken a room. Pull open the sides of a BreatheRight nose strip (they work for me, though may be placebo effect). Notice the blue light coming from the separating adhesive.
 A: From Wikipedia:

Triboluminescence is an optical phenomenon in which light is generated through the breaking of chemical bonds in a material when it is pulled apart, ripped, scratched, crushed, or rubbed (see tribology). The phenomenon is not fully understood, but appears to be caused by the separation and reunification of electrical charges. Triboluminescence can be observed when breaking sugar crystals and peeling adhesive tapes.
... While investigating triboluminescence, researchers discovered that static electricity could cause low-pressure air to glow. This discovery revealed the possibility of electric lighting.
... Upon fracture of asymmetrical materials, charge is separated. When the charges recombine, the electric discharge ionizes the surrounding air, causing a flash of light. Research further suggests that crystals which display triboluminescence must lack symmetry and be poor conductors.

A: 
luminescence, general term applied to all forms of cool light, i.e., light emitted by sources other than a hot, incandescent body, such as a blackbody radiator. Luminescence is caused by the movement of electrons within a substance from more energetic states to less energetic states. There are many types of luminescence, including chemiluminescence, produced by certain chemical reactions, chiefly oxidations, at low temperatures; electroluminescence, produced by electric discharges, which may appear when silk or fur is stroked or when adhesive surfaces are separated; and triboluminescence, produced by rubbing or crushing crystals.

italics mine.
For two surfaces to adhere strongly, the atoms/molecules composing each reach, when produced, the lowest energy level in the contact region, possibly by releasing thermal photons. That is what adhesion means, strong bonds between molecules, i.e. common energy levels that create one "body". The energy provided by pulling the strip breaks these bonds  and forces electrons in the outer levels of the surfaces to relocate, by falling into new lower energy levels specific to each surface and releasing a photon. In this case the photons are in the optical wavelength region and produce luminescense.
