This time of year, we see people on the Internet claiming that Christmas lights are causing problems on their wifi network. While this is certainly technically possible, the real chances of this type of interference causing a wifi problem is actually quite low. Be sure not to plug those strings of light in the same outlet as your wifi router just to play it safe and should you think there is interference, it's really easy to test it out. Just check your connection speed with and without the lights plugged in at a speed test site like http://speedtest.net. Your Wi-Fi signal is much more likely to be interfered with by your microwave oven, old cordless phones, a baby monitor or most likely from your neighbor's wifi router competing with yours. If your Wi-Fi router doesn't automatically find the least congested radio channel, for 2.4 Ghz signals, the best channels to use are 1, 6 and 11 because they tend to have the least amount of signal overlap from other channels. Android smartphone users can also us a free app called WiFi Analyzer (http://wifianalyzer.mobi) that can also help.