The previous synopsis is incorrect - the ghost inhabits the body of a movie dummy, not an alien - overall, a movie worth watching. Basically the story of a guy getting cheated out of his inheritance, and going after it, with the help of a ghost, who also needs his help. The special effects are worth watching, and the acting was actually fairly good. The plot was a bit thin, but still enjoyable. It is always fun for me to watch the efforts of those making these types of films over 25 years ago. Before the big budget special effects we can do now with CGI and such.
It is also worthwhile to note that some of these actors went on to do much greater works, and that this was where they honed their talent, among other performances they had already done.