While at dinner after FFF we tried to repair a failed turn signal switch (multifunction switch). Turns out they are relatively easy to take apart and don't have a lot of springs, etc. inside to lose. Just gently drill out the two hollow rivets (we used a pocket knife tip to scrape away the flared end) and gently pry apart the body of the switch. Inside is a small "V" shaped contact piece that is loose and can fall out. It makes the contact for left and right turn signals and the contact points get dirty. Note that they can conduct enough to show good on a meter but still not enough to make the turn signals blink. Just clean the contact points and reassemble.
There is one tricky part to the reassembly. Besides having the little "V" contactor piece in the correct place (pretty obvious) you need to put the black plastic slider for the head light flasher/high beam switch over the end of the white plastic "foot" that moves it up and down before putting the switch back together. The black part has a slot on one side that the "foot" rides in so it will be moved both ways. And make sure the parts stay in the right place as you put it together.
You could use small bolts to hold it together but I used safety wire through the rivet holes which seems to work just fine.