GFCI: found out two things I did not know:....need self threading green ground screws to place in metal outlet box empty holes; and the screws on the GFCI outlet are tapered on the ends and cannot be screwed back unless ends sanded down or replacement screws not tapered are handy to replace the "dead" screws........working in dark was not happy to learn those two bits of minute info for a seemingly "easy" DIY.