She is referring to climate change. A weird curly light-bulb is an energy saving light-bulb.
Basically, she is saying that she doesn't go for all that climate-change, global warming talk. One of the major campaigns of the climate change groups is the increased use of energy-saving light bulbs, with their hope that they will thereby "save the world".
Due to the promotion of energy-saving light-bulbs, old-fashioned incandescent light-bulbs are now almost impossible to get (I can't get them anymore in Australia).
I just found on Wikipedia that "light bulbs" is one of Bachman's "passions":
Bachmann introduced the Light Bulb Freedom of Choice Act, which would require a GAO report show that a change to fluorescent bulbs (CFLs) would have "clear economic, health and environmental benefits" prior to enforcement of lighting efficiency regulations that effectively ban conventional light bulbs. Bachmann argued, "Each light bulb contains between 3–6 milligrams of mercury. There's a question about how that mercury will fill up our landfills, and also if you break one in your home, you'll have mercury that instantaneously vaporizes in your home. That poses a very real threat to children, disabled people, pets, senior citizens. And I just think it's very important that Americans have the choice to decide, would they like an incandescent or a (CFL)?" Bob Collins of Minnesota Public Radio commented on the debate, noting a Popular Mechanics article which concluded that over the average life span of a CFL, an incandescent bulb could result in the emission of more mercury than an equivalent CFL, even if the CFL was broken, assuming power was generated by "a coal-fired power plant" (which produce about half the electricity the U.S. consumes). However, Collins also noted there is evidence that "[for] some people, CFLs are a health risk" and that the environmental risks of CFLs deserve consideration.
Add that to the fact that she doesn't believe global warming is true, so that makes sense:
Bachmann has charged that global warming is a hoax and has been a vocal skeptic of global warming. She has asserted that since carbon dioxide is "a natural byproduct of nature", it is a beneficial gas required by plant life. She stated that because life requires carbon dioxide and it is part of the planet's life cycle, it cannot be harmful. In a statement she made on the House floor on Earth Day, April 22, 2009, Bachmann stated she was against the cap and trade climate legislation, stating: "Carbon dioxide is not a harmful gas, it is a harmless gas. Carbon dioxide is natural; it is not harmful.... We're being told we have to reduce this natural substance to create an arbitrary reduction in something that is naturally occurring in the earth.
Thus, by saying "America safe for old-fasioned light-bulbs", she is declaring her belief in that global warming is not true, therefore light-saving light bulbs are not necessary, and therefore the incandescent light-bulbs, which have been nearly wiped out with the introduction of light-saving light bulbs, will be safe, if she is elected.