Well, you probably could find a ghost with it. I hear that their presence is betrayed by a sudden temperature drop.
Buried metal will quickly achieve temperature equilibrium with its environment.
Thought experiment.
Let us say for the moment, that there indeed is a bar of gold, buried
under the ground, that happens to have a temperature that is a few degrees higher than its surrounding. Forget how this could happen, let's just assume that it could.
Then, at the interface between the surface of the gold bar and the ground, we would expect that the material in contact with the gold bar will experience a temperature increase and come up to the same temperature as on the gold's surface. In the process of doing that, it pulled some heat out of the gold bar.
The other atoms in the ground close to the interface material, will have their temperature increased as well. Simply because if there is a temperature differential between them, heat energy will be transferred.
This process will continue and keep pulling heat energy out of the gold bar until the temperature of the gold is in equilibrium with the surrounding dirt.
So, after this process has happened you come with your electronic thermometer and what do you see? Nada!