My gas in mixing with my oil in a 1992 ford explorer what is causing this and how do i fix it

Change the intake manifold gasket, that means taking the whole top part of the engine apart.

Locate the fuel injectors just above the engine valve covers. There are six injectors, each pointing to a cylinder. All of the injectors are mounted to a chrome fuel supply tube. Mounted to the chrome tube is a fuel pressure regulator, it is about the diameter of a silver dollar and has a vacuum line mounted to it. Start the engine and remove the vacuum line. If gas comes out of the regulator vacuum port the regulator is leaking and fuel is being drawn into the engine via the vacuum line. If its leaking replace the fuel pressure regulator.

Most times that is caused by one or more cylinders mis-firing or a bad injector. Can also happen if temp sender is not functioning correctly, causing the engine to think it's cold all the time (t-stat can also do that)
Many larger parts stores do free code tests which may be helpful if there is any problem with an engine sensor. If the problem isn't obvious, likely that is the best way to begin.

This is probably a stuck fuel injector. you may be able to determine which one by examining your spark plugs. But you must fix this before running that or you will ruin the engine. The oil will break down and wipe out the engine bearings.