Stranger things HAVE happened...

But if you search on the Internet, you can find plans to make your own incubator fairly cheaply. Eggs generally need a balance of humidity and heat in order to develop properly. Offsets in either can cause problems with the hatch, and dead or disfigured/improperly formed chicks. :( Styrofoam coolers are one thing that may work. :)

Velvet ~:>

I was following a thread on backyard chickens about a person incubating eggs in an electric fry pan. I'm not sure how it ended up.
What kind of chickens are they? You might have better luck leaving the eggs with the hen and when she gets enough eggs in her nest hope that she goes broody.
Make sure the hens have an area where they can hide their nest. They like to get behind something where it's quiet.
Good luck, let us know if your incubating idea works.

What about temperature, do you have a thermometer? If not you are leaving a lot to chance. The home made brooders I have seen were usually enclosed, but had some vent holes in it. I also wouldn't mist the eggs, at least for chickens. The humidity tray should be sufficient.

Like velvet said, you might want to try a styrofoam cooler.

I built my own little incubator and had great success...I made a square "wooden" box with a hardware cloth rack a cake pan for water and a wafer for adjusting temp using 2 40 watt bulbs...it worked beautifully.

I've now built a little incubator using a styrofoam cooler, a glass lid and a 40 watt light. I keep the glass lid with a 2 inch gap to give air flow and regulate the temperature. I have a thermometer at the level of the eggs putting the temp at 100 degreens. The eggs are resting in an egg carton with a little layer of water under the egg carton for humidity. I rotate the eggs by hand 2-3xs per day. I moved all my eggs I was trying to hatch in the open to this contraption and I'm adding eggs as my hens are laying them. If I didn't ruin the first batch, I should have my first hatchlings in 10 days.