First off, I'm using a Braun electric shaver (cordless).
As you can see from the picture this is the inside of the shaver:-

The white plastic piece at the bottom of the picture is the moving part on the shaver, this is what the razor blade attatches too (this creates the vibration)
The next picture is the inside of the shaver, you can see that I've pushed a screw through the white plastic piece (this will act as my vibration needle)

For the vibration needle I ground down a 2 inch screw on my grinder, leaving a small amount of thread, so it can be screwed into the plastic.
On the last picture, I've assembled the electric pick and covered it in plastic tape making sure I left cut-outs for the on/off button and also the charging hole.

I also made another one out of an electric tooth brush although I found it didn't have enough power, however it still opened afew locks.

All in all they were quite easy to make it took me about half an hour.
Hope you like them
Harry