oil preassure switch leak?

[Speednis]

A cursory search came up empty on this one.

I have a 2000 XE V6 with 109,000 miles. It has developed a nasty oil leak that started in the past few months when I switched to synthetic oil. I've heard that switching like that can cause oil leaks. It looks like its coming out of the oil preassure switch that is located right behind the oil filter. When I unplug the wire harness from the switch, the inside of the rubber boot (around the wire harness) is filled with oil. I'm not 100% sure that this is the source though. Has anyone else had an oil leak there, and if so, about how much is a replacement switch?