Accessories such as headsets for electronic devices are provided. A headset may be provided with a button controller assembly that has user-actuated buttons and a microphone. The microphone may be formed by mounting a microphone transducer on a printed circuit board. A housing may be mounted over the transducer to form a sealed cavity for the transducer. Circuitry may be mounted on portions of the printed circuit board that extend beyond the edges of the microphone housing. The button controller assembly may have dome switches. The dome switches may have a housing that encloses dome switch components and that forms a structural internal part for the button controller. The dome switch housing structure may have tabs or other engagement features that mate with corresponding engagement features in a button member. The button member may be pressed by a user to actuate a desired dome switch.