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 and a traditional switch surface cover, the traditional switch having a protruding portion extended above the traditional switch surface cover, the traditional switch device being used for receiving a first user manual operation to control a target device connected to the traditional switch device via an electrical wire, the retrofit switch apparatus comprising:

• a cover body having a storing space for containing and covering the traditional switch to keep the traditional switch in a default operation mode;
• a control cover attached on a top side of the cover body for receiving a user operation associated to the target device;
• a control decoder disposed under a first end of the control cover for converting the user operation to an electrical signal;
• a wireless transmitter disposed under a second end of the control cover and connected to the control decoder with a wire for wirelessly sending a control instruction associated to the electronic signal to the target device to control the target device, wherein the cover body comprises a top plate disposed with an elastic component engaging the control cover for providing elastic force to recover the control cover to an original position after a user releases control over the control cover.