Fear, like other emotions, can be transferred in animals if it is conditioned to a specific stimulus. Instrumental conditioning shows the sound as a primary stimulus and a secondary stimulus of aversion that produce the phobic behavior, and the extinction process is established by a frequency of the primary sound stimulus. The purpose of this study is to demonstrate the extinction of electrical phobic aversion in a single case of a CD 1 mouse through the pre-experimental design, where in the first phase the acquisition of phobia occurs through conditioned stimulus such as sound and electric current. In the second phase, the extinction process by removing the secondary stimulus. According to the objective, the result of this intervention was the extinction in 70% of the phobic aversion to electric shocks in the CD1 strain through conditioned stimulus. The experiment lays out the first clues of the responses manifested by the mouse in each trial, and this information will be useful to know the frequency and duration of these phobic behaviors in the stage of acquisition and elimination of the phobia.