Do they make a 12v light relay for solid on and wigwag?

my brother has recently purchased a truck and is looking to put a light bar on it, the truck came with a plow and naturally he picked up a few driveways.. for a safety messure i would like to make it so the light bar has both solid light capabilities as well as wigwag capabilities. is there a controlable single pole double throw relay you can buy in order to make this work? if not how would i go about making this happen? thank you in advance for all the help