dash lights going nutz

If anyone could help, that would be great.... here is goes, I have a Tribute, 2001, and lately my dashlight has been going crazy, the light won't turn on when I put my headlights on, now tonight I found out I have no taillights either.  When I put my left signal on, the dashes and brake lights flash.  IMy 1st thought was bulbs, so I replaced them all, that didn't work, then I thought fuses, but test meters shows they are good.  Now I thinking ground, damn I hope not, that could take awhile to figure out which ground it is.  If anyone has had this happen before and fixed it could they let me know.  I hoping its simple, but doesn't look good.
 
Thanks
 
C.Anderson