#1- mike dies, boss or whoever at publishing company(I think) gets a package from Mike,and its a manuscript of 1408 that is thick,like a few hundred pages long. He begins to read it,as various bits of dialogue from earlier and throughout the film play,and the camera pans back,through the office,doors slam shut..fade to black as final voice over plays.

#2 similar too theatrical ending. Only Mikes wife does not hear the daughter and mike on the recorder. Mike then turns off the recorder and holds cuddles it in away and it fades to black.

Mike dies. After the burial when the editor and Mike's wife are about to get into the car Samuel L. Jackson approaches them. He offers Mike's wife the box of his belongings that were found after the fire mentioning that Mike "didn't die in vain". Editor gives him the look. Mike's wife says that's not how she'd want to remember him. They get into the car. Sam Jackson listens to the tape recorder in his car. Listens to the part about himself. Then Mike's daughter's voice is playing saying "Daddy". Mr. Jackson looks in the rear-view mirror and sees a little girl. He looks again. AAAAAHHHHHH! (JUMP SCARE HERE). He drops the recorder. He looks again. The little girl and her father leave the cemetery (just some random people). SLJ drives off. Dissolve to the burnt hotel room 1408. Mike is walking around. The he hears his daughter's voice calling "daddy!'. He says "Oh yes..." and disappears while walking through the room's door.
The end