A plug-in type dispenser of liquid volatiles, such as insecticides, fragrants, and the like, of the type having a heater for evaporating the liquid volatiles from a wick, provides improved volatile dispersion characteristics and in-use indication. Air flow through the dispenser and around the wick is increased, and the outlet is sized and configured to avoid condensation on the inside and outside of the housing as well as to increase the vertical component of the expelled air stream. An internal lamp transmits light to be reflected off of an exterior in-use indicator surface of the housing to provide visual indication that the dispenser is active.