Can a bad switch cause a drain on your car battery?

i had a car that showed a drain on my car battery with the ignition switch off. i hooked a test light up to the battery, and noticed when i changed out the combo lever switch on the steering column , the light went out, i thought a switch just opened or closed an electrical path, and was not an electrical load... show more i had a car that showed a drain on my car battery with the ignition switch off. i hooked a test light up to the battery, and noticed when i changed out the combo lever switch on the steering column , the light went out, i thought a switch just opened or closed an electrical path, and was not an electrical load itself. i have heard people say you have a bad ground problem. with there not being a light or some type of electrical device that appears to be on, what else could be draining my battery. thanks for any tips.
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