Contact electrification during the formation of adhesive bonds can lead to transient electrical signals and even electrical discharges when these bonds are subsequently broken. We present detailed measurements of the electrical current generated by peeling a pressure sensitive adhesive from an electropolished Cu substrate in air and in vacuum. The magnitude of this current depends strongly upon the peel speed. At constant peel speed, transient fluctuations in the rate of interfacial failure along the peel front produce corresponding current fluctuations. Electrical breakdown events during peel produce sharp spikes in the current signal as well as long wavelength electromagnetic radiation and visible/UV emissions with characteristic spectral features. We use these signals to characterize the breakdown events in various atmospheres. Current measurements are a potentially new time-resolved probe of micromechanical and electrical processes accompanying peeling.