Device for securing a mouse ball

A seal for a computer mouse that includes a housing having a bottom wall that defines an opening, a retainer plate fitted in the opening and formed with a circular hole, and a mouse ball in the housing and projecting through the circular hole, the seal comprising a sheet-form piece of self-adhesive material defining a hole that is larger than the circular hole in the retainer plate, and wherein the seal has an extent such that when it is applied to the retainer plate with the hole in the seal concentric with the hole in the retainer plate, the seal adheres to both the bottom wall of the housing and the retainer plate, whereby removal of the retainer plate from the opening is resisted, and wherein the seal is formed with at least one line of weakness and the adhesive is selected relative to tensile strength of the seal across the line of weakness such that the seal adheres to at least the retainer plate with a force that exceeds the tensile strength of the seal across the line of weakness, whereby the seal breaks into at least two fragments when force is applied tending to remove the seal from the retainer plate.