It is coming on intermittently.

That is the brake pad wear warning light.

It is activated when a contact on the brake pads makes contact with the brake disc. This completes a circuit & illuminates the light. It is coming on intermittently because the pad contact is only just contacting the disc, minute movement is enough to make or break contact & therefore the light will come on & off. Eventually the light will stay on permenantly & u will need to replace ur brake pads before they wear down to the iron back plates & wreck the disc surface.

The other possibility is that the wire to the brake pads has rubbed through & is making & breaking contact somewhere else (like the caliper) though this is less likely.