a comma or a period?

[theol]

1. A man screeched, "a ghost!", he was so scared that he passed out.
2. A man screeched, "a ghost!". He was so scared that he passed out.

Should I use a comma or period?

 

[Hermione Golightly]

A period. You have two separate sentences and a comma doesn't join sentences. A colon might be suitable.

 

[Azarosa]

A man screeched, "a ghost!". He was so scared that he passed out.

 

[Cenzontle]

Neither comma nor period: the exclamation point is considered sufficient to mark the end of the first sentence.
A man screeched, "a ghost!" He was so scared that he passed out.