How to tell if your phone is tapped?
Find an extension cord and plug it in the area around your phone and any other nearby electronic devices.
To make sure that a particular phone line is tapped, find an extension cord, plug it into the tap’s wire at one end, then follow from end to end on the outside of the house until you penetrate. Expect to be charged for this service if you’re not on “the job”. If you do this without permission or warrant and don’t have reasonable suspicion of criminal activity going on inside your abode, don’t expect it to go well in court.