4years old scared of imaginary spiders and cockroach

It is 1AM,and before tonight my was scared of everything to the point that sometime he could not use the bathroom alone.It happens usually around thanksgiving,so we figured out it because of the masks but,tonight he suddenly woke up crying,screaming saying that there is a spider in his bed.I checked and there was nothing.we took him to our bedroom but he would still time to time look around and start screaming that he sees a cockroach or a spider,sometimes a mosquito.he was so scared that he did not want to sit on the bed,even on his mom's lap he did not feel safe.we enventually managed to calm him down but he would still suddenly scream and look around like if there was something.I just put some cartoons,he is still scary but he is watching the tv.my question is can this be a behavior sickness?do i need to take him to a psychologist?My son is a triplet,his brother and sister are doing fine and sleeping like babies.

[margypops]

Has anything scary upset him, any other family members been talking about scary stuff has he watched any movies, at Halloween there are a lot of stuff on TV what about Babysitters , teen love to scare kids ,hopefully unintentionally ask him why he is afraid, why would he think there was a spider in his bed and has anyone else said anything to make him unhappy.I dont think he has anything wrong ,no sickness, but if you are concerned speak to your Doctor .,

[djanea]

2:16 AM thanks for your comment margypops
I just woke up again,same story as yesterday.my son suddenly woke up screaming there is a spider in his bed.I'm in his bed room now.I am going to talk to the doctor today.
thanks

[margypops]

You didnt answer the question has anyone been scaring him ? I agree that a visit to the Doctor is a good thing .