I want to remove an old switch and replace it with a T5225 Combination switch. BUT, I only have 3 wires going into the box. Plus the white wire is the live wire as I determined with my wire tester

SOURCE: hampton bay ceiling fan

we have a hampton bay fan burning smell coming in didnot run

SOURCE: Dimmer Switch Installation issue

ALL you really need to worry about is the white and black wire that you hooked up before. The green ground screw is not needed. If you have a bare wire completely bare all the way, you can hook it to the green, but it is not required to work.
The other 2 screws are for the switch. It does not matter which wire goes where, as the switch just puts them together, and takes them apart.

SOURCE: Wiring to a 3 single pole combination switch

run 14-2 wire to power switches, then run one 14-3 wire and one 14-2 up to fixture..you will have an extra neutral but its okay... just tie all nuetrals together....this gives you the needed 3 hot wires!

SOURCE: wiring a leviton 5625-W switch receptacle combination

You cannot replace the switch with a switch/receptacle combo because there is no neutral wire. The black and white that you see are both used as hot wires. One is the Line and the other is the Load.

You have to install another 2 wire cable or replace the existing with a 3-wire cable. A 3-wire cable has a black, red, and white, plus the bare ground wire

SOURCE: GE digital timer. Instructions say to: 1)

Find the Hot wire:
Your switch has 2 wires. One of these wires is Hot, and one goes to load. Disconnect wires from switch. Turn on power. Do not stand on wet surface. Test each wire to bare copper wire. When tester lights up, that is Hot wire. The other wire goes to load.

Connect wires:
Hot wire goes to Black timer wire
Wire to load goes to Red timer wire
White wire connects to white wires that are twisted together
Bare copper wire connects to Green wire from timer

How to connect white wire to white wires that are twisted together.
a) Strip white timer wire so you have 1-1/2 " of bare wire. Stranded wire will wrap around other wires easily.
b) Remove wire nut. DO NOT UNTWIST wires.
c) Hold all whites together so bare copper lines up. Wrap stranded copper around the twisted wire.
d) Replace wire nut, or use larger wire nut. Twist real tight. Do not use tape. You can solder the connection.
e) When done, pull on white time wire to make sure it is held tight. Push whites back into box.