I was getting the tingling from the swr meter and the radio had not been powered up for probably 18 hours, that was making me think about static electricity. The fence post the mast is mounted to is probably in the ground a foot maybe but after no rain for a month and 40 mph winds static could have been getting back inside I suppose
A static buildup, and IF (a big if) it were the case, would not cause "tingling",
just a one time arc discharge until it built up again to sufficient potential.
You have a ground fault methinks.
Doesn't matter if the rig was not "powered up".
Many radios have voltage flowing through them even while "off".
Was the power supply on during this "18 hour power down"?
It's also unclear as to whether the rig was on/off/receving/transmitting
when you felt the "tingling" in the meter. You just said "had not
been powered up for 18 hours".
This is a puzzler.
73, Ken AD6KA