I've used a wireless mouse for almost two years and never been asked to turn it off. Probably b/c the range on these things is pitiful, at most 2-3 feet.
That may be true of your particular mouse's wireless technology. However, a typical
Bluetooth Class 2 wireless mouse will get you
30 feet easy, in my experience.
There's even Bluetooth
Class 1 out there, which will get you up to 300 feet!
Folks often use both for controlling their laptops from across the room during video presentations.