I have got a Taylor 312ce 12-fret. I actually rarely plugged it in at home, but I did now due to a new pedalboard. Thereby, I discovered a hum issue.
The simplest setup on which it occurs is:
Guitar --> acoustic amp
In this setup, the hum disappears if I touch the cable and the guitar strings. Considering that this is a grounding issue, the internet states that it should be sufficient to touch the strings. This however does not work alone and even does not make any sense to me, since I am not grounded either.
Guitar --> effects --> boss looper --> acoustic amp
In this setup I can even make the hum disappear by touching the metal body of the looper.
An amplified recording of the hum (ignore the other noise, it is introduced by an external preamp which is another issue) can be found here. The hum in this recording disappears while touching strings and cable. I do that a few times.
Since the hum only disappears if I touch the strings and ground myself somewhere I do not consider this question as a duplicate. I would rather like to formulate the question as: Is it normal for my guitar that touching the strings alone does not stop the humming?