Questions
Why does my mouse double click when I click once?
Usually the switch under the button is worn or dirty, so one press makes contact twice. Static charge, a weak battery in a wireless mouse or a driver setting can cause it too.
What threshold should I use?
80 ms catches most faulty switches without flagging normal clicking. If your own deliberate clicks get flagged, lower it; if you suspect a fault with longer gaps, raise it.
How do I fix a mouse that double clicks?
Unplug it and press the buttons a few times, try another port or fresh batteries, and clean around the button. If the test still finds double clicks, the switch needs to be replaced.
Does it test the right and side buttons?
Yes. Left, right, middle, back and forward are counted separately, and each one has its own double click count.