As a professional pest controller I would advise you to save your money.
These electrical devices have a limited effectiveness, if your home has a mouse and you plug in the device it may be scared away, however if you have an infestation or your premises/home provide a better life for them than elsewhere they will simply get use to the noise.
I have used this once. But, to be very true, it is of no use. I would suggest you to take the help of the professional pest controllers in this regard. I am staying at Australia and have taken the help of them to get rid of the pest. You can log on to the below mention link. From them I took the help. The website is http://www.pestfreesydney.com.au/ .