A window-attached alerting device (10) having an electronics circuit (12) that is enclosed within an alerting device enclosure (40) that includes an outer side (42) and an inner side (44). The outer side (42) is removably attached to an inner surface (62) of a windowpane (60) that is attached to a building. Since the enclosure (40) is attached to the inside of the building, the enclosure is not exposed to inclement weather or to theft. The outer side (42) of the enclosure (40) is visible through the windowpane (60) and includes indicia (52) in the form of a target (54) or the like that is positioned to encompass an electrode (22). When a person places his/her finger or hand proximate to the target (54) the electrode, in combination with the electronics circuit (12), produces an alerting device signal 31 that can be easily heard within the building.