One effective method of removing wax from carpet is to harden the wax using ice, and scrape away the excess wax. After removing the hardened wax, use an iron to melt the remaining wax, and soak it up with a paper towel or grocery bag.
While there is a temptation to begin cleanup of the wax as quickly as possible, it is important to avoid spreading the spilled wax while attempting to clean it. Cool the wax with ice to prevent it from spreading further. Scrape away the excess wax with a blunt object, such as a butter knife, to reduce the chances of it spreading deeper into the carpet when the iron applies heat.
After removing the excess hardened wax, use heat to melt it to a liquid again, so that the absorbent material can remove it. A paper towel or paper grocery bag provides an easily disposable material that readily absorbs the excess wax.
Protect the carpet by setting the iron to its lowest setting. At this temperature, it is hot enough to melt candle wax, but not so hot that it melts synthetic carpet fibers. Press the iron over the paper towel or bag to melt the wax, and apply pressure to remove it from the fibers. Continue applying fresh paper towels, heating and pressing until the wax is gone, if possible.