There is an electrical humming sound coming from a Wemos D1 Mini v2 module.
I'm using a 5 V, 3 A power supply connected to a 5 V input pin. I suspect it's the current input which causes the sparking/humming sound. There is no heating of device as such.
What is the recommended current supply for D1 Mini module. Will it harm module in long run?
Check this out: What might be the cause of high pitch sound coming from a switching regulator circuit
It usually happens when you draw too low current than the power supply is designed for. However, it harms neither the supply nor the load. If the noise is disturbing, I would recommend using a higher quality power supply.
I have used many different versions of the Wemos D1 boards. From my experience they only typically require about 100ma with occasional peaks up to 150ma. They can run on 3-6 volts. If your power supply is >6 volts I would recommend using a buck-boost converter (not a linear voltage regulator!) so you can control the output voltage and the converter will adjust for the under/over power supply.
The D1 mini is a fairly bare bones module with no mechanical parts, no large inductors, no switching regulator, no large capacitors. It does a 12 mhz crystal but that's really about it.
Small caps or the crystal could vibrate to cause a hum, indicating a bad design or possibly failing part, but no guess as to how long it would go before failure.
Since the noise coming from the d1 and not the power supply, its unlikely to be due to the power supply's high current capacity directly. Current is pulled. Your supply could be rippling and that could noise and performance issue. Your supply could have a large minimum current for best performance so you could try with a different supply.
