Let the battery drain until it is totally empty, then try to restore your ipod.
1. Ensure that you have an active Internet connection as new versions of iTunes and iPod Software may need to be downloaded to your computer.
2. Download and install the latest version of iTunes if you do not already have it installed.
3. Open iTunes, and then connect iPod shuffle to your computer.
4. After a few moments, iPod shuffle will appear in the Devices section on the left side of the Tunes window.
5. Select iPod shuffle under Devices and you will see information about it appear in the main iTunes window under theSummary tab for iPod shuffle (3rd generation) or the Settings tab for iPod shuffle (1st or 2nd generation).
6. The Version section tells you whether iPod shuffle is up to date or needs a newer version of the software.
7. Click the Restore button. You will be presented with one or more restore options that may prompt iTunes to automatically download the latest iPod Software. The 4-possible restore options are:
8. * Restore Option 1: Restore – Restores with same iPod Software version already on iPod. * Restore Option 2: Use Same Version – Restores with same iPod Software version already on iPod even though a newer version is available. * Restore Option 3: Use Newest Version – Restores with the latest iPod Software currently on your computer. * Restore Option 4: Restore and Update – Restores after downloading the latest iPod Software on your computer.
9. If you are using a Mac, a message will appear prompting you to enter an administrator’s name and password.
10. A progress indicator will appear on the computer screen indicating that the restore process has started. Do not disconnect iPod shuffle during the restore process.
11. After the restore process is complete, the iPod shuffle’s status light will flash orange continuously. The iPod Setup Assistant window will appear asking you to name your iPod and choose your syncing preferences as you did when you connected your iPod shuffle for the first time.
Now if that is not possible, I would start thinking about disassembling the iPod and to replace the switch as well as the battery....Good luck.