Intermittent blinking interior lights

I have a 1999 Windstar and just recently the interior lights (dome, floor, door) have started blinking occasionally. When they do they are like a strobe light until I turn on the engine and then they stop. My son was driving the other night and he said that the dash board lights were blinking for a few minutes which has never happened before. Any suggestions?

I have a 1999 and the interieor lights blink off and on while going down the road. They do this very randomly and the only thing that keeps them off is turning the dimmer control all the way down until it clicks and turns them off. I can't imagine what switch or wire could cause this as most of these things work when grounded and it could be a pinched or scraped wire. But where??????? I hope someone replys as this is starting to be very annoying and being a fixer I can't stand that I have no where to start to get at fixing it. Please help. Thanks.

I believe this problem can be caused by a number of issues.

The first thing I found that worked for me was to clean the door sensors. They are optical and can be cleaned with contact cleaner. You should be able to find other posts in this forum that describe the method of doing so.

The same thing happened to my '99 3.8.

Turned out to be the driver door switch. I just disconnected the wires at the plug and no more blinking lights. The downside is you no longer get an interior light when opening the driver door, but that was a trade off I was willing to make.