Conductivity (sigma) measurements are performed on micellar systems consisting of tetradecyltrymethylammonium bromide (TTAB) in the presence of n-butanol (BuOH). It is found that sigma vs BuOH molarity dependence at fixed TTAB concentration shows an unusual sinusoidal behavior. Other parameters of the systems are studied and an approximation to the conductivity of the system is made. The unusual dependence of conductivity on alcohol concentration at fixed surfactant concentration is discussed and some evidence of the competition of the viscosity of water-alcohol solution and the degree of ionization on conductivity of the systems are presented, rather than a phase transition as it was proposed earlier.