The oil pressure sending unit (aka: switch in some parts stores) is located directly above the oil filter, not by the distributor. Still sounds like an oil pressure sending unit to me. You could verify with a mechanical gauge if you're ambitious but if it were me, I'd buy a replacement sender directly from Jeep for best reliability/mating/accuracy with your factory gauge.
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!