Why does my mouse double click by itself?
Check whether your mouse is double clicking on its own, and test how fast you can double click. Single presses that register as two clicks are one of the most common mouse faults, and this test catches them: it opens in double-click mode, counts genuine double-clicks per second, and flags any press pairs closer than 15 ms that only a faulty switch can produce.
Inside every mouse button is a small switch with metal contacts. As it wears or oxidises, the contacts can bounce when pressed, and the mouse reports two clicks instead of one. Firmware normally filters this with a debounce delay, but once the bounce lasts longer than that delay, double clicks get through. You notice it as files opening when you meant to select them, or drag-and-drop letting go mid-drag.
