Water heater stopped working

We have a 30 gal (from memory) electric hot water heater in the attic over the second bedroom. In the bathroom underneath is a wall switch which allows us to turn it off when unneeded, and it is off 99% of the time.

There is power TO the switch as indicated by a pocket hot circuit tester, and FROM the switch when in the "on" position, but no hot water.

Since there is power from the switch when it is in the "ON" position, I think I need to see if there is power AT the hot water heater (which there probably is).

If there is power, then would the element need replacing?

Do water heater elements ever get damaged in electrical storms? Is there another possibility?

Since this is a "guest" bedroom, the heater probably has not been on more than 100 days in the 9.5 years it has been in place and so should not be "worn out". We have a rainwater system, and rainwater is acidic, so maybe that is not a good thing for electric hot water heaters?

The heater is a bit of a challenge to get to so I want to take any necessary tools with me on the first trip.

What am I looking for and what can I test? What tools will be needed?

Thanks.