http://www.cellspyapp.info/how-to-tell-if-cell-phone-is-spyware-bugged-tapped.htm

How to tell if your cell phone is tapped - do you have phone tapping spyware application installed on your cell phone?? Here are some telltale signs:

You cell phone battery is draining faster than normal or faster than it use to.

Your cell phone lights up as if it is possessed. You phones screen light may come on briefly for no apparent reason even if it is just sitting there.

Battery is warm even if phone has not been used.

Phone is slow to shut down.

Background noise while in a call. If spyware has been installed that taps live conversations you may here static or a clicking noise while you are in a conversation.