Vibration sensor used in a horizontal application

I've read the other posts and contacted the manufacturers' of the sensors but have come to the conclusion they won't work for my application. This is my application, I have a vase of water, when the vase makes a vibration I need a sensor to read it from the bottom. (So the vase will be essentially set on top of a box, and the sensor will be in between the vase and the box. When this sensor senses a vibration I need it to send a signal to my relay so it will switch. Currently I have a toggle switch hooked up and it works ( i just switch it back and forth manually when i see the vibration) however, I want to find a vibration switch that will essentially do this for me so I won't need to use a toggle switch.

I'm thinking a vibration sensor from a car alarm system but I first don't know how those work and second can not find JUST the sensor I find the entire car alarm system.

Thanks in advance

A Radio Shack project book had a vibration sensor (earthquake detector), made from a magnet and a nearby coil picking up any bouncing in the magnet.

The magnet was suspended from a beam. Your project might require suspending the magnet between 3 or 4 springs, arranged horizontally.

Another possible method is a mirror, suspended the same way, reflecting light to a photodetector.