There are digital meters that give you an accurate voltage reading. Test the outlet to see what voltage is supplied. You may want to test other outlets as well. In Connecticut, the utility company is regulated to supply voltage between -5% to +3% of 120V or 114V -123.6V.I thought the lighting circuits should be on different circuit than outlets. The reasoning is that if you trip a circuit at night, you won't be left in the dark.