I have power to the driver side switch, and one faint bit of power to the passenger side switch, but only on one wire.
Better details, like what color the wire is and how much voltage is read, would make helping you troubleshoot it easier for us.
BUT, just with what information that you have provided, I would first do the following:
1) Clean the passenger window switch
on both sides. Use an aerosol spray "electrical contact cleaner, safe for plastics". Spray down into the switches (ignition key off) while you work the rocker switch back and forth. You'll get a better cleaning by pulling the switches out of the door panel, so that you can also spray into the back of the switch.
2) If cleaning the switches doesn't work, check for a broken wire inside the wiring harness between the door and the cowling. The flexing of the wiring harness over time can break the wire's copper strands, and in many cases the wire's plastic insulation will be intact but the copper strands inside it are broken. Broken wires like this are more common on the driver side; the driver's door gets used more. In some cases, with ignition key on and holding the passenger window switch, wiggling the door harness will get you a response from the window motor as the broken wire ends touch one another across the break.
There could be other possibilities, but these are the most likely, and should be looked at first.
Welcome to TRS.