Q.I Have A Tree Growing In A Brick Post That Carries Electricity. It’s In A Old Church Wall.
I need to kill the tree. It is busting the bricks out from the post. But I’m concerned about killing the plants in the garden at the bottom of the post.

Certified GKH Gardening Expert
Unfortunately, you may have no choice but to sacrifice the plants to avoid a dangerous situation. The responsibility of yours' and others' safety, as well as electrical equipment safety will have to be paramount.
On top of this, a professional will need to be called. Removing the tree could leave a void that may need to be filled in order to restore any destroyed foundation or destroyed structural integrity.
I would contact your local extension services, or utility services to see what they have to say about your situation.