[GWN7]

I'm wondering if there was a baseboard heater and it was removed (replaced with the in the wall heater) and someone just added a little wire to make the new location work.

How safe is it? No junction box. Wires not protected or installed at the right height. Wire may be too small for the run to the new heater. Is heater properly grounded?

Perfectly safe till something happens and then your insurance company cancels your claim.

Hire electrician, pull permit, open wall, rewire properly, have inspected, close wall (new drywall), paint and forget about it.

Or use glue to put new baseboards on and remember to never drive a nail into that wall. Cross fingers.