You should be aware that anywhere that a ground rod is installed, that there may be AC voltage/current/frequency in the vicinity of it.

Stray voltage/current/frequency is the most serious form of exposure. Electrocution kills very few people per year. Stray voltage/current/frequency exposure is suspected to be making people sick in the millions!

Electrical earth (ground) cables are all energized with radio frequencies (RF). Generally the further away from the ground rod you go, the more RF that you will find.