I am not a native English speaker. I was wondering how to express the situation in which one uses a tool for something other than what it was meant to be, and in a bad way so that you are not doing your best, or you are hurting yourself with your ignorance about the tool you use.
There is a related proverb, that says:
If all you have is a hammer, everything looks like a nail
which means, according to the Wiktionary:
With limited tools, single-minded people apply them inappropriately or indiscriminately
If a person is familiar with a certain, single subject/has with them a certain, single instrument, they may have a confirmation bias to believe that it is the answer to/involved in everything.
A common phrase for this is:
You're trying to fit a square peg in a round hole.
The idea is that you can't fit a square peg in a round hole; you should be using a circular peg instead.
Other than that, feel free to pick your favorite from one of these:
You're using the wrong tool.
You should use a voltage meter.
You shouldn't use an ammeter, because you're trying to measure voltage, not current.
You might find this easier if you use a compass, instead.