A few years back I had to replace a 4x8
sign and the posts.This
sign had been there for at least ten years. I Had the location checked just in case. Turned out telephone company had buried a fiber optic line in between the two posts since the old
sign had been installed.
None of the installers I use would touch the job, the telephone company ended up sending a contractor remove and install the new posts and didn't charge me or the customer a penny.