Changing a switch for a porch light

He should sell the porch and get a ferrari.

Possibly he miswired the switch, using a spdt where he should have used spst, then somehow inadvertently connecting those other loads to the "off" position

…a wild guess

Not knowing how many wires are in the box or what the down stream load are I will have to make some assumptions. You connection acts like your husband has not connected the grounded circuit conductors(white) correctly. If the down stream GCC(white) is connected to the load side of the switch, when the switch is closed (on) there is no potential difference on the down stream loads so they do not operate but the porch fixture also on the load side of the switch will operate. When the switch of open the down stream loads get their GCC(White) connection through the porch fixture lamp so the loads appear to be working. The best thing to do is remove the switch, identify the conductors and make the correct connections. All the GCC (Whites) should be connected together, One of the black conductors will be the supply (feed) and whould be connected to the other blacks that supply the down stream loads and one side of the switch. Then there will be one black that goes to the porch light and you connect that to the load side of the switch. Hope that is not too confusing. If you do not have a tester you can turn off the power, connect all the whites together then connect all the blacks together. Turn the power on and the porch light will come on. Then turn off the power and remove one black, power on and see if porch light comes on. When the porch light does not come on and one of the down stream loads is working you have found the porch light black that goes on the load side of the switch.

I like Bha's guess better

Usu black is hot, white is neutral, and green or bare is earth ground, which connects to the metal outlet box. Sometimes there's a red, which might be secondary hot. Although they're at about the same potential don't get earth ground mixed up with neutral

Your hubby might acquire a voltohmmeter and learn to use it