LED activation by proximity with radio?

Other Hardware Product Design
1

I am trying to create a device where an LED will start to glow when another object gets within range of it. Sort of like a glowing sword when goblins get close kind of deal. I was thinking that this may be achievable via radio in some way. One object broadcasting and the other object waiting to receive and when it gets the signal it activates until the broadcasting object gets out of range.

So...
Is this doable?
Am I on the right track on how this might be done?
What kind of range do you think we can get with it still being somewhat small... at least on the receiver side.
Any advice?

edit: I'd love to get the distance to be at 100 - 500 feet if possible.

Receiver should in theory be able to be built into a prop sword.

Thanks!

2

You need to give the forum some idea of whats distances are involved and in terms of the receiver what size 'somewhat small' actually is.

3

Apple AirTags are an example of the basic idea. Look up key finders like Tile, SmartTag and Chipolo, too.

4

I'd love to get the distance to be at 100 - 500 feet if possible.

Receiver should in theory be able to be built into a prop sword.

5

Could a smartag or key finder item be made to activate LEDs?

6

Probably not by a beginner, but there are plenty of small, Arduino-compatible MCU+Bluetooth radio modules, if you want to start a long journey.

One example.