I have a small panel with 3 LED lights a stop switch and a bell.
I have the same panel 15 meters away .
What type of wire can I use not in pipe.

You need to supply us with much more information. Just for instance, what is the electrical load that will be carried by the conductors.

Are you trying to set up a secondary panel to the first panel or are you building a new panel independent of the first panel.

Yep, this is a weird question. Without more info it's hard.

I do recommend that the panels power supplies be separate and only interface the panels with a contact closure.

So if you want to turn on a light. A dry contact/relay goes in panel A

Panel B contains the power supply for the LED and a relay. Panel B contains the power supply for LED in panel B.

Don't power indicatiors directly from a panel far away.

I know.

Fire alarm and thermostat wire come to mind. Depending on the location, you may need plenum cable.

Fire alarm cable is usually red with a PTFE insulation. Tstat cable is usually brown and should be available plenum rated.

Make sure your contacts are driven at least at 10 mA