vibration activated delay ciruit
Try increasing the value of the 1k (on the vibration switch) to 5k or 10k, and increase R1 to 20k or more.  That should slow down the "on" delay.   

Then place a high value resistor across C1 to ground, (about 2x or 3x the value of R1). That should quicken up the delay off.  

To optimize the resistor values temporarily replace R1 and the new resistor across C1 with 100k potentiometers, adjust till you get the desired delays, then measure the potentiometer values and re-install resistors of that value.  (Just be sure you don't set both potentiometers to zero - cause you'll burn out transistors with just a little delay....)