If it's the indicators that just stay on solid, it's not the hazard switch. Water in the electrics or a dodgey wire or something. If they were flashing as though the hazard switch was on, then yeah, could be that.
I'd say just take out the fuse for the lights (not sure if the indicators are on a seperate fuse or if all the lights are on one fuse. Might have to ring a mobile mechanic or the AA or some shit if they are... or you could risk running to a garage in it.
By the way, if the lights are on solid, what happens when you indicate, or put the hazard switch on?