Why do hazard lights keep turning themselves on when my 1998 Mercedes is parked in driveway

replace hazard light relay ,and hazard light switch if needed.

have you installed an aftermarket alarm system? if so it was a lousy job.

You have constant power to the hazard switch. Replace the switch. it is shorting out.

Do the hazard lights work ?

check remote batteries for replacement. they may be dead as for the door locks and trunk. as for the fog light, parking brakes situation a short would make them not work. not stay on. the electrical would be fused for that. a short prevents electric from getting to the load or device. i would not think that fog lights would be linked to parking brakes. did you mean parking brake light? the fog lights should be on a switch by themselves or connected to main headlamps

sounds like the hazard switch is bad. take it off and try another.

sounds like the battery in the remote is old and dead and needs to be replaced. ( could also be the electric door lock fuse ).
if you are also experiencing trouble with your door locks themselves turning - then try and spray some teflon or silicone base lubrication in all the locks to wash out any dirt or debris.

c...

Howdy, No Big Deal, Follow this, Common Power To Left and Right Signal , orange wire to flasher relay for left black wire for right, there are two relays inside flasher module 1 the left and right signal share the other is for the hazards. The is a common ground for the signal lights and hazard so if one side works good ground if the hazard works good ground...maybe power wire from 320 dollar turn signal unit maybe 160 on ebay....hope this helps keep smiling.....Doug in Clermont, Florida

possible headlight relay under plastic screwed down cover behind fuses.

I had the same problem twice before. Solved it the same way both times. In my case it was the Hazard switch at the top of the steering column. It was stuck. I knew it was that because the signal lights had been functioning perfectly until I parked my car alongside the road with the hazard lights on to do some nighttime fishing and sip a little white lightnin'. (just kiddin' about the white lightnin')

When I got back in my car to go, I turned off the hazard lights but I had no turn signal lights! So I kept pushing that hazard button up and down for about 30 times with my left turn signal arm down until it started working again. So after having this happen to me twice, I learned a valuable lesson: Don't ever use hazard signals in this car.