Hopefully this is just a combination of the dry winter air with various materials in your environment. You can get anti-static mats that are used for electronics work, perhaps they would make a decent mouse pad. They also have wrist straps, but those would be a pain to take on and off whenever you want to get up.
A more universal solution is to get a humidifier for the home. The humidity helps remove any build up. But don't turn it up too high since you don't want mildew or mold problems, and you don't want to create condensation issues in the windows.
Beyond that, review what materials you have separating you from a ground. I'm currently on carpeting, with a plastic chair mat, on a chair with plastic wheels and a fabric seat. In the winter time here, I'm a shock hazard. I may just try one of those anti-static mats.