Not much chance of very high voltage lines anywhere near a residence. Residential voltages are deadly enough, depending on your grounding path. High lines feeding residential pole transformers are 24,000 V, and that WILL jump about 1/2" to a grounded conductor. Your 240 volt entrance lines are insulated, and that is sufficient to prevent to prevent shock, unless your metal antenna cuts the insulation when falling. If you touch either of the "hot" wires, it is only (!) 120 volts to ground.
I have a large ham beam antenna on my house, but no where near any AC power.
Floyd