Retrofit switch

A retrofit switch apparatus for being attached to a traditional switch device, the traditional switch device being fixed to an environment surface and having a traditional switch mounted on a traditional switch cover surface of the traditional switch device used for accepting a first user manual operation to control a target device connected to the traditional switch device with an electrical wire, the retrofit switch apparatus comprising:

• an attaching device for attaching to the traditional switch cover surface;
• a retrofit housing connected to the attaching device for providing a containing space for covering the traditional switch so as to keep the traditional switch remaining a predetermined operation status when the attaching device being attached to the traditional switch cover surface;
• and
• a touch module supported by the retrofit housing, the touch module having a touch surface and a driver circuit, the touch surface being for receiving a second user manual operation processed by the driver circuit, wherein the second user manual operation is associated with the function of the first user manual operation, wherein
• the touch surface of the touch module has a movable connection and the retrofit housing having a detachable connection and the driver circuit providing a wireless control to the target device, wherein the attaching device has a first mode and a second mode, the traditional switch is covered by the retrofit housing and kept untouchable from a user in the first mode, and a part of the retrofit housing is moved for exposing the traditional switch to the user in the second mode for the user to operate the traditional switch.