How can one determine if an electrical current is an alternating or direct?

I have an L.E.D. nite lite that had a momentary switch to change between the different colors. During modification, I snipped the wires off from the switch & it went AWOL. Now it cannot be found. However I happen to have a pair of SPST momentary pushon switches for 3A @ 125VAC (or half the amps at doubled voltage). I dunno if it would be of help, but I do have a digital multimeter. And while I can appreciate any concerns anyone might have regarding the safety of me & my surroundings, I don't need any lecture about being careful. As I take necessary precautions, such as using a fused power strip which can quickly be turned off should smoke arise & while it's not 100% fail proof it's better than just plugging into a wall outlet. Sorry if that comes off snooty, but surely one can understand my point. As always, I'd certainly appreciate any help regarding this question.