Path Light setup inquiry

Hello,
I need advise about a simple transformer setup in my home. Originally, I had a pole lamp in the front yard which I have removed. What is left is the capped hardwiring that protrudes from below grade. In the basement, from an electrical box/light, extends a 120V wire to the basement wall. From there, the wire exits the basement through the cement block (through a drilled hole)and extends, below grade, 10 ft. to where a pole lamp used to exist. There is no conduit as yet. The ends of the 120V wire reach 1 ft. out of the ground and are capped off, temporarily. I wish to add a transformer within the basement to step down the current to 14V for a 14V 100W path light. This will be the ONLY light on that wire. I will not need a transformer for several lights. I've noticed step-down transformers that are the size of large shoe boxes but they are primarily for several light arrays. I only need it to work on the one. Can you suggest an appropriate transformer for one 14v Halogen 100W path light and can it reside inside the basement as opposed to an exterior box? Any other directions would be taken seriously.
Thanks for reading. Below is a simplified diagram of my situation.
Al

Most of the big box stores will have low quality plug-in transformers for landscape lighting. For your installation you will need to reconfigure the inside wiring to have a 120v outlet to plug it into. You will also need to install either a switch, a timer, or a photocell unit to control the on/off cycling of the unit.

Thanks, I also get the impression that I have little choice but to place a GFCI outlet outside instead and run off of that. I'm learning as fast as I can.

There is no reason why you cannot install the transformer in the basement if you think there is a good reason to do so.

That's my answer.

Thanks, CacherChick. I'm going to do that. If I have trouble with "supposed" heat buildup, I'll just change it. It's only one light on a timer so I can't imagine a life or death issue.

Regards,
Al

The transformer hangs on the wall and plugs into an outlet. It will probably have a built in timer. There will be NO heat buildup.

Power = volts * amps, or 100w/14v ~ 7.2A. So, keep the existing 14g wire. A smaller wire could be used. When using low-voltage lights, keep in mind that to get the same watts, you need more amps verses line voltage. A second 100W bulb on that transformer would just about max out that 14g wire. On line voltage, a 100W bulb uses 100w/120v ~ 0.83A. This is one reason much of the world uses 220vac, they can get the same power through using smaller wires. This discounts the safety issues.

Most of those transformers say to only use outside.