I had this problem tons of times and even transferring the black tape from the original digitizer didn't always fix the job since its all about the tiny layer of kapton tape underneath the thicker black one and this layer sometimes gets wrinkled.
Bought a big roll of Kapton tape off ebay and ever since I use it to tape off everything that looks like coltan or metal on my ipad mini's and airs, no more problems at all! Kapton tape is basically insulating-heat resistant tape and for some reason its the only one fixing this problem.
Other causes of ghost touch can be that the corners are bent, putting a stress on the screen or that you damaged the digitizer flex, although in my experience 95% of the time the Kapton tape does the job!