abs light question

[gen3usa]

lwhen i start the car, nothing comes on, place it in gear and nothing wrong, after about 25' the light comes on, resets after ignition is off, but the light comes on only every other time, not every time. does each wheel have a sensor that could be going bad? i also saw a post that someone had bad bearings and it would trigger the light. any info would be awesome.

thanks