upright freezer fermentation chamber. No defrost... what to use for heat?

$50 upright freezer on CL. STC-1000 from eBay, a few odds and ends.. BAM! Fermentation chamber.

However, the coils went through each of the shelves, so I had to CAREFULLY bend one layer of coils back so I could build a shelf and get a few fermenters in there. Quickly found that I am fluctuating from about 17.9-18.9°C. The STC-1000 is set to 18.5 with a .3 variance. Not too bad, but not quite as controllable as I would like.

I guess this is not a frost free one as there is a bit of condensation from when it's on. So, I realize I need some form of heat source to kick on so I can maintain better temp stability. Since there is condensation, I am hesitant to do the paint can heater... or anything else really that involves electricity as Water + Electricity. = House Fire...

So to the question: What can I SAFELY use to add heat when needed? Or, just RDWHAHB and let it fluctuate a ~1°C throughout the day?

Forgot pics

I have a similar set up and us a small cinder block with a light bulb placed inside it. Works great.

Can you post a picture please? Thanks for the response

Here you go. I sit the block on a piece of reflectix foil. The bulb is 60 watts. It is plugged into my temperature controller.

Any fermentation chamber is going to have condensation, there's no way around it. There's been a few other threads talking about it and i know some people invested in these...

http://www.amazon.com/dp/B000H0XFCS/?tag=skimlinks_replacement-20

Its on my wishlist and i plan on picking one up before my next brew. I know some people get the cans of the silicate stuff and put them in their as well to help absorb the moisture.

This is what i use for heat and it works well but the paint can idea is a bit cheaper.
http://www.amazon.com/dp/B003XDTWN2/?tag=skimlinks_replacement-20

I have an upright freezer similar to this one, and for heat I use that same lasko heater. It works fantastic. Nearly instant heat, no fire hazards, and doesn't draw much power

By the way, I have an STC 1000 that powers two outlets. The cooling outlet has the jumper tab broken off, the heating outlet keeps the jumper tab. The reason I did that was because one side of the cooling outlet is hot at all times to power my stir plate. On the heating side I decided to keep the tab. The other side of the heating outlet powers a computer fan to help circulate the hot air. Works great for me

Very clever wiring! Thanks for the links. I'm leaning towards the Lasko so I don't have to worry about wiring a lighting rig, though both options seems to be cheap, and effective methods.