Most folks drill a hole in the pan for the sensor. Not to many other places you can put it.
If you do have RTV in the filter and you are sure that is what it is you need to dig in a bit more to the engine. Do you see any RTV on the timing cover or edge of the
oil pan?
If you can see it all spread out the sides you will need to pull it and clean all of it out.
Just a few months ago one of our customers brought us his 70 Roadrunner 440-6 car after he took it someplace else closer to where he lives. He had some other shop replace a bad part on his car and wanted us to look it over because he was not happy with the work. When I lifted the car and look under it I could see black RTV leaking out all around the pan gasket. When I asked him about it he told me that the other shop had told him the gasket was leaking and needed to be fixed. He had told them to go ahead. I showed him all the RTV and told him we need to pull the pan and get all of the RTV out of the pan. He was not real happy about it until I got the pan off of it and showed him all the RTV that had fallen off the inside of the pan and was now plugging the
oil pump screen. Saved his engine and he was happy with us and pissed at the other shop. A LITTLE RTV is ok. Give you an idea I may use 2 tubes a year on engines. A little goes a long way to much can cause BIG problems.