How to Take only 5V from Arduino without GND ??

how to take 5v only from arduino without GND to power the relay ??

as the Pic show ,take 5v to power the relay but the GND from NodeMCU ...is this Right ???

Think: 5V relative to what?

Just so ...

There must always be a circuit for current to flow too

Take a decent picture (in daylight) or provide a schematic (photo of hand-drawn is fine).
Provide a link to the relay board or a decent picture of it.

Note on GND:
Looks like you’re currently providing the ground connections via the USB cables; that is, if both NodeMCU and Arduino are connected to the PC. Try the same exercise powering the Arduino Uno from e.g. a cell-phone charger and see if it works.

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