If you are referring to Bluetooth (as opposed to a typical mouse protocol), then it's a large and complex standard with many protocols/modes, rather like like USB.
Like USB, it has an HID (Human Interface Device - bt.org link) profile, which is used for mice, keyboards, game controllers, pointing devices, etc.
There is also the RFCOMM mode you may want to look at, which essentially emulates a serial port like RS232. You can obtain cheap and easy to use modules that can act as a server or client in this mode (e.g. I have used one here in a prototype device, purchased from eBay for ~£5 in a quantity of 5)
All the major vendors like Digikey, Mouser, Farnell do various BT modules. Also, as mentioned, have a look on eBay for "Bluetooth Module HC-05".