Hello there!
I am deeply sorry for now getting an answer for this question.
To be quick, your two words should be Log and Fog.
The first would be "Log" since a piece of wood could be known as a log
The second would be "Fog" because lighthouses are only used for low visibility or to help a ship find its way. In most cases, they are used for fog.
If you need anymore help, don't hesitate to message me!
Have a great day
God Bless!
@X8lue83rryX