can you please say or describe the light, does it indicate your brakes are on, or does it indicate that you have an engine fault?
if it is the engine then it may be a dodgy sensor, it may be indicating a fault that doesn't exist.
any half decent garage would figure it out in no time.
Not sure what the Peugot one looks like but if it is similar to this - ( ! ) I would suspect the brake fluid level is low or the brake pads are worn and neeed replacing or the handbrake switch is faulty.
When does it go off and on ?
If it does when going round a bend I suspect the brake fluid is low - as the brake pads/shoes wear the fluid level drops and there is a sensor fitted in the brake fluid reservoir to let you know.
If you are not sure about cars get someone to look at it for you to be on the safe side - the fluid level can also go down due to a leak in the system - which ain't good.
As Mr T says let us know what the light looks like.