Monsters in closet

Autumn

I’m stressed and don’t know what to do. My son turn 2 in June. Since then ivehad a little girl we potty trained him and just recently put him in a toddler bed.

He’s been doing great until tonight. He told my mom this evening

“Mommy reads me a book I go to bed then monsters come”

I was worried but didn’t put too much thought into it unti tonight. He goes to bed at 8:30 and since he was 9 months old has gone straight to bed no issues. Tonight he was up about 7 or 8 times and would not go to sleep. Said it was hard and there were monsters. We had to close closet door and move his bed back. We took his crib out today (he’s been in toddler bed about a week but just removed crib) and cleaned his room up. Could that be the cause? How did you overcome this? I hate the thought of him being scared. 😕